which of the following elements is the most reactive? Chlorine Bromine Fluorine Helium

Answers

Answer 1

Answer:

Fluorine is the most reactive

Explanation:

Among the halogens, fluorine, chlorine, bromine, and iodine, fluorine is the most reactive one. It forms compounds with all other elements except the noble gases helium (He), neon (Ne) and argon (Ar), whereas stable compounds with krypton (Kr) and xenon (Xe) are formed.


Related Questions

A projectile is fired with an initial speed of 36.6 m/s at an angle of 42.2° above the horizontal on a long flat firing range. Determine (a) the maximum height reached by the projectile, (b) the total time in the air, (c) the total horizontal distance covered (that is, the range), and (d) the speed of the projectile 1.50 s after firing.

Answers

Answer:

Explanation:

a) Maximum height id expressed as;

H = u²sin² theta/2g

H = 36.6²(sin42.2)²/2(9.8)

H = 1,339.56(0.6717)/19.6

H = 899.81/19.6

H = 45.91m

Hence the maximum height is 45.91m

b) The Time of flight is the total time in air expressed as;

T = 2usin theta/g

T = 2(36.6)sin42.2/9.8

T = 73.2sin42.2/9.8

T = 49.17/9.8

T = 5.017secs

Hence the total time in air is 5.017scs

c) Range = U²sin2(theta)/g

Range = 36.6²sin2(42.2)/9.8

Range = 1,339.5(0.9952)/9.8

Range = 1,333.11/9.8

Range = 136.03m

Hence the range is 136.03m

d) USing the rime of flight formula;

T =2Usintheta/g

1.5 = 2Usin42.2/9.8

2Usin42.2 =1.5*9.8

2Usin42.2 = 14.7

U = 14.7/2sin42.2

U = 14.7/1.3434

U = 10.94m/s

Hence the speed of the projectile is 10.94m/s

A car is accelerated at a constant rate from 15 m/s to 25 m/s. It takes the car 6 s to reach its final speed. What is the car’s acceleration?

Answers

Answer:

1.67 m/s²

Explanation:

The car’s acceleration can be found by using the formula

[tex]a = \frac{v - u}{t} \\ [/tex]

where

v is the final velocity

u is the initial velocity

t is the time taken

a is the acceleration

From the question we have

[tex]a = \frac{25 - 15}{6} = \frac{10}{6} = \frac{5}{3} \\ = 1.666666...[/tex]

We have the final answer as

1.67 m/s²

Hope this helps you

A centripetal force of 210 N acts on a 1,600-kg satellite moving with a speed of 5,500 m/s in a circular orbit around a planet. What is the radius of its orbit?

Answers

Answer:

230476.19km

Explanation:

Step one:

given

Force F= 210N

mass m= 1600kg

velocity v=5500m/s

Step two

Required is the radius r

the expression for the force is

[tex]F_c = \frac{mv^2}{r}[/tex]

substitute

210=1600*5500^2/r

cross multiply we have

210r=48400000000

divide both side by 210

r=230476190.476m

r=230476.19km

A copper collar is to fit tightly about a steel shaft whose diameter is 6.0000 cm at 19°C. The inside diameter of the copper collar at that temperature is 5.9800 cm. To what temperature must the copper collar be raised so that it will just slip on the steel shaft, assuming the temperature of both the steel shaft and copper collar are raised simultaneously?

Answers

Answer:

T' = 865.15 °C

Explanation:

In order for the copper collar to just slip on the steel shaft the, assuming are heated simultaneously, we must find the final parameters of both and equate them. Because the final diameters of both must be same for the slipping to occur.

FOR COPPER COLLAR:

dc' = dc(1 + ∝c*ΔT)

where,

dc' = final diameter of copper ring

dc = initial diameter of copper ring = 5.98 cm

∝c = coefficient of linear expansion for copper = 16 x 10⁻⁶ °C⁻¹

ΔT = Change in Temperature

Therefore,

dc' = (5.98 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT]   ------------- equation (1)

FOR STEEL SHAFT:

ds' = ds(1 + ∝s*ΔT)

where,

ds' = final diameter of steel shaft

ds = initial diameter of steel shaft = 6 cm

∝s = coefficient of linear expansion for steel = 12 x 10⁻⁶ °C⁻¹

ΔT = Change in Temperature

Therefore,

dc' = (6 cm)[1 + (12 x 10⁻⁶ °C⁻¹)ΔT]   ------------- equation (2)

Comparing equation (1) and equation (2):

(5.98 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT] = (6 cm)[1 + (12 x 10⁻⁶ °C⁻¹)ΔT]

(5.98 cm/6 cm)[1 + (16 x 10⁻⁶ °C⁻¹)ΔT] = [1 + (12 x 10⁻⁶ °C⁻¹)ΔT]

0.9967 + (1.59 x 10⁻⁵ °C⁻¹)ΔT = 1 + (12 x 10⁻⁶ °C⁻¹)ΔT

1 - 0.9967 = [(15.9 -12) x 10⁻⁶ °C⁻¹]ΔT

0.0033/3.9 x 10⁻⁶ °C⁻¹ = ΔT

ΔT = 846.15 °C

but,

ΔT = T' - T = T' - 19°C = 846.15°C

T' = 846.15 °C + 19 °C

T' = 865.15 °C

what makes the ball stop on rolling after somtime​

Answers

A ball stops because the surface on which it rolls resists its motion. So the ball stops because of friction.

A stone is dropped from a bridge 45 meters above the surface of a river. What is the time required for the stone to reach the water’s surface?

Answers

Answer:

C.  3.0 s

Explanation:

Well, I've taken this question before, so I went back and this was the answer I put, which was correct.

Hope this helps! <3 May I have brainliest if it helps you enough?

It will take 3 s for the stone to get to the surface of the water.

We'll begin by listing out what was given from the question. This includes:

Height (h) = 45 m

Time (t) =?

NOTE: Acceleration due to gravity (g) is 10 m/s²

From the data above, we can obtain the time taken for the stone to get to the surface of the water as follow:

H = ½gt²

45 = ½ × 10 × t²

45 = 5 × t²

Divide both side by 5

[tex]t^{2} = \frac{45}{5} \\\\t^{2} = 9[/tex]

Take the square root of both side

[tex]t = \sqrt{9}[/tex]

t = 3 s

Therefore, it will take 3 s for the stone to get to the surface of the water.

Learn more: https://brainly.com/question/19339518

2. A solenoid. Suppose the south end of a bar magnet was introduced to the right end of this solenoid at a constant velocity. What direction would you expect the induced magnetic field to be in?4. To decrease the magnitude of current induced in the inductor using a bar magnet, you could (select all that apply):a. Decrease the strength of the magnet.b. Decrease the velocity of the magnet going into the solenoid.c. Decrease the number of coils in the solenoid.d. Increase the cross sectional area of the solenoid.6. List the TWO values you need to record to measure a voltage on the oscilloscope

Answers

Answer:

2) deflection must be towards the negative side of the voltage.

4) the correct statements are: b and c

Explanation:

2) This question is based on Faraday's law of induction, when we introduce a magnet in a solenoid an induced current is produced that generates a voltage that is given by

           E = - N d [tex]\phi_{B}[/tex] / dt

where [tex]\phi_{B}[/tex] = B. A

The bold are vectors

Therefore, when applying this formula to our case, the induction lines of the magnetic field increase as we approach the solenoid, as the South pole approaches the lines are in the direction of the magnet, therefore the normal to the solenoid that has an outgoing direction and the magnetic field has 180º between them and the cos 180 = -1; consequently the deflection must be towards the negative side of the voltage.

4) From the Faraday equation we can see that the inductive electromotive force depends

* The magnitude of B that changes over time

* The area of ​​the loop that changes over time

* The angle between B and the area that changes over time

* A combination of the above

With this analysis we will review the different alternatives given

a) False. It takes a temporary change and an absolute value of B

b) True. As the speed decreases, the change in B decreases, that is, dB / dt decreases

c) True. The current is induced in each turn, if there is a smaller number the total current will be smaller

d) False. A temporary change of area is needed, in addition to increasing the area the current increases

We can see that the correct statements are: b and c

A distant galaxy has a redshift z = 5.82 and a recessional velocity vr = 287,000 km/s (about 96% of the speed of light.) Notice that the equation z=vrcz=vrc does not hold true for recessional velocities approaching the speed of light. What is the distance to the galaxy in light years?

Answers

Answer: 4100 Mpc

Explanation:

Since H o = 70 km/s/Mpc

Redshift z = 5.82

Recessional velocity vr = 287,000 km/s

Then, the distance to the galaxy in light years will be:

= Recessional velocity / H o

= 287000 / 70

= 4100 Mpc

An ant can run at an average speed of 0.083 meters per second, calculate how long it would take an ant to run 100 meter dash in seconds and in minutes

Answers

Answer:

The time taken by the ant is 1204.82 seconds or 20.08 minutes

Explanation:

Given:

Speed of the ant (s) = 0.083 m/s

Distance traveled by the ant (D) = 100 m

We know that distance traveled by a body is equal to the product of the speed of the body and the time taken for its travel.

Let the time taken by the ant be 't' seconds.

Now, as per the formula:

Distance = Speed × Time

⇒ 100 m = 0.083 m/s × t

⇒ [tex]t = (100\ m)/(0.083\ m/s)[/tex]

[tex]\therefore t=1204.82\ s[/tex]

Now, we know that,

60 seconds = 1 minute

So, 1 second = [tex]\frac{1}{60}\ min[/tex]

Therefore, [tex]1204.82\ s = \frac{1204.82}{60}=20.08\ min[/tex]

Hence, the time taken by the ant is 1204.82 seconds or 20.08 minutes

A spaceship is accelerating at 1000 m/sec2 . How much force is required from the backthrusters to completely stop the spaceship?

Answers

Answer:

1000x Newton

Explanation:

Step one

given data

acceleration= 1000 m/s²

The question did not specify the mass of the mass of the space ship.

So, let's assume the mass is x kg

Step two:

Required is the force F in Newton

From Newtons first law, it states that a body will continue to be at rest or uniform motion unless acted upon by a force.

F=mass x Acceleration

F=ma

Substituting our given data we have

F=1000x Newton

A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.00 m/s, and her takeoff point is 1.90 m above the pool.

Required:
a. What is her highest point above the board?
b. How long a time are her feet in the air?
c. What is her velocity when her feet hit the water?

Answers

Answer:

a = 1.152s

b = 0.817 m

c = 7.29m/s

Explanation: let the following

From the first equation of linear motion

V = u+at..........1

parameters be represented as :

t = Time taken

v = Final velocity

a = Acceleration due to gravity = 9.8m/s²

u = Initial velocity = 4 m/s

s = Displacement

V = 0

Substitute the values into equation 1

0 = 4-9.8(t)

-4 = -9.8t

t = 4/9.8

t = 0.408s

From : s = ut+1/2at^2.........2

S = 4×0.408+0.5(-9.8)×0.408^2

S= 1.632-4.9(0.166)

S = 1.632-0.815

S = 0.817m

Her highest height above the board is 0.817 m

Total height she would fall is 0.817+1.90 = 2.717 m

From equation 2

s = ut+1/2at^2

2.717 m = 0t+0.5(9.8)t^2

2.717 m = 0+4.9t^2

2.717 m = 4.9t^2

2.717/4.9 = t^2

0.554 =t^2

t =√0.554

t = 0.744s

Hence, her feet were in the air for 0.744+0.408seconds

= 1.152s

Also recall from equation 1

V= u+at

V = 0+9.8(0.744)

V = 7.29m/s

Hence, the velocity when she hits the water is 7.29m/s

Finally,

a = 1.152s

b = 0.817 m

c = 7.29m/s

_______mirrors or lenses always produce smaller images.​

Answers

Answer:

The images produced by a convex mirror are smaller than the object it reflects. The image produced by a concave lens is always virtual. The image in a convex mirror is always upright and is smaller than the object.

Explanation:

:)

List Five examples from daily life in which you see periodic motion caused by a pendulum
(Marking Brainliest)

Answers

Answer:

by a rocking chair, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave.

Explanation:

A plane is flying due west at 34 m/s. It encounters a wind blowing at 19 m/s south. Find the resultant veloci

Answers

Answer:

The resultant velocity has a magnitude of 38.95 m/s

Explanation:

Vector Addition

Given two vectors defined as:

[tex]\vec v_1=(x_1,y_1)[/tex]

[tex]\vec v_2=(x_2,y_2)[/tex]

The sum of the vectors is:

[tex]\vec v=(x_1+x_2,y_1+y_2)[/tex]

The magnitude of a vector can be calculated by

[tex]d=\sqrt{x^2+y^2}[/tex]

Where x and y are the rectangular components of the vector.

We have a plane flying due west at 34 m/s. Its velocity vector is:

[tex]\vec v_1=(-34,0)[/tex]

The wind blows at 19 m/s south, thus:

[tex]\vec v_2=(0,-19)[/tex]

The sum of both velocities gives the resultant velocity:

[tex]\vec v =(-34,-19)[/tex]

The magnitude of this velocity is:

[tex]d=\sqrt{(-34)^2+(-19)^2}[/tex]

[tex]d=\sqrt{1156+361}=\sqrt{1517}[/tex]

d = 38.95 m/s

The resultant velocity has a magnitude of 38.95 m/s

A body of moment of inertia I=0.80kgm2 about a fixed axis, rotating with constant angular velocity of 100 rad s-1, then torque acting on it will be:

a)80Nm

b)zero

c)160Nm

d)120Nm

Answers

The torque acting on it will be zero.

Two solid spheres are made from the same material, but one has twice the diameter of the other. Which sphere will have the greater bulk modulus?

Answers

Answer:

It will be the same for both

Explanation:

from this question we have one similarity between these two spheres.

- they are both made from the same material,

The difference between both spheres is that:

- one of the spheres has its diameter to be twice as large as that of the other one.

We are to say the sphere with the greater bulk modulus.

If the material is the same thenthe Bulk modulus is also the same. It is not dependent on the material since it is a constant for that materia

Therefore the correct answer is:

It will be the same for both spheres.

If the particles were moving with a speed much less than c, the magnitude of the momentum of the second particle would be twice that of the first. However, what is the ratio of the magnitudes of momentum for these relativistic particles?

Answers

Answer:

p₂ / p₁ = 2 (v₁ / v₂)

Explanation:

The moment is a very useful concept, since it is one of the quantities that is conserved during shocks and explosions, for which it had to be redefined to be consistent with special relativity,

         p = m v / √[1+ (v/c)² ]

for the case of speeds much lower than the speed of light this expression is close to

         p = m v

 

In this exercise they indicate that the moment of the second particle is twice the moment of the first, when their velocities are small

        p₂ = 2 p₁

       p₂/p₁ = 2

in consecuense

       m v₂ = 2 m v₁

       v₂ = 2 v₁

consider particles of equal mass.

By the time their speeds increase they enter the relativistic regime

        p₂ = mv₂ /√(1 + v₂² /c²)

        p₁ = m v₁ /√(1 + v₁² / c²)

let's look for the relationship between these two moments

       p₂ / p₁ = mv₂ / mv₁   [√ (1+ v₁² / c²) /√ (1 + v₂² / c²)

       

from the initial statement

      p₂ / p₁ = 2 √(c² + v₁²) / (c² + v₂²)

we take c from the root

      p₂ / p₁ = 2 √ [(1+ v₁²) / (1 + v₂²)]

this is the exact result, to have an approximate shape suppose that the velocities are much greater than 1

      p₂ / p₁ = 2 √ [v₁² / v₂²] = 2 √ [(v₁ / v₂)²]

      p₂ / p₁ = 2 (v₁ / v₂)

we see the value of the moment depends on the speed of the particles

What average force is required to stop an 1100-kg car in 8.0s if the car is travelling at 95km/h?

Answers

Answer: 13062.5 N

What average force is required to stop an 1100-kg car in 8.0 s if it is traveling at 95 km/h? i got the answer to be 13062.

Answer:

The answer is 13062.5 Newtons (N).

Explanation:

The mass of the car is 1100 kg.

The acceleration is 95 km/h.

Using this information, we can use Newton's 2nd Law, F=MA.

1100 kg * 95km/h = 104500 N

Because the answer wants average force, we need to divide the answer by 8 seconds, giving us 13062.5 N.

104500 N / 8 seconds = 13062.5 N (avg force).

A cheetah can maintain a maximum constant velocity of 34.2 m/s for 8.70 s. What is

the displacement the cheetah covered at that velocity?

Answers

Answer:

297.54m

Explanation:

step one:

given data

velocity v=34.2m/s

time t= 8.7s

Step two

Required is the distance the cheetah has covered on the condition

we know that speed= distance/time

make distance subject of formula we have

distance= velocity *time

distance= 34.2*8.7

distance = 297.54m

Therefore the displacement the cheetah covered at that velocity

is 297.54m

A velocity vector has magnitude 100.0 m/s and make an angle of 160o with the positive x-axis. Determine the x- and y-components of the vector.

Answers

Answer:

Vₓ = -93.96 m/s

Vy = 34.2 m/s

Explanation:

The x-component of the velocity vector can be given as follows:

Vₓ = V Cos θ

where,

Vₓ = x-component of velocity vector = ?

V = Magnitude of Velocity Vector = 100 m/s

θ = Angle with positive x-axis = 160°

Therefore,

Vₓ = (100 m/s)Cos 160°

Vₓ = -93.96 m/s

The y-component of the velocity vector can be given as follows:

Vy = V Sin θ

where,

Vy = y-component of velocity vector = ?

V = Magnitude of Velocity Vector = 100 m/s

θ = Angle with positive x-axis = 160°

Therefore,

Vy = (100 m/s)Sin 160°

Vy = 34.2 m/s

A rifle of mass M is initially at rest but free to recoil. It fires a bullet of mass m and velocity v (relative to the ground). After firing, the velocity of the rifle (relative to the ground) is:_____.a. –mv.
b. –Mv/m.
c. –mv/M.
d. –v.
e. mv/M.

Answers

Answer: Option C) -mv / M is the correct answer

Explanation:

given that;

A rifle of mass M is initially at rest but free to recoil

velocity = v

using conversation of moment

pi = pf

i.e initial moment = final moment

But initial moment was zero (0) since everything  was rest but free to recoil

so

pi = pf

0 = mv + MV

V is the recoil velocity of the rifle

MV = -mv

V = -mv / M

Therefore Option C) -mv / M is the correct answer

Akia is balancing the equation Na + H2O NaOH + H2. He tries to find the coefficients that will balance the equation. How could he find the correct coefficients? by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products by counting the total atoms and making sure the number of atoms in the reactants is the same as the number of atoms in the products by counting the total mass of each compound and making sure the reactants have more mass than the products by counting the mass of each atom and making sure the reactants are more massive than the products

Answers

Answer:

by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products. - This is the answer.

Explanation:

Answer:

its A(by counting each individual atom and making sure the number of each kind of atom is the same in the reactants and the products

Explanation:

Suppose a popular FM radio station broadcasts radio waves with a frequency of 96. MHz. Calculate the wavelength of these radio waves. Be sure your answer has the correct number of significant digits.

Answers

Answer:

3.125 meters.

Explanation:

(3.0*10^8)/(96*10^6)

= 3.125 meters.

Hope this helped!

A small object moves along the x-axis with acceleration ax(t) = −(0.0320m/s3)(15.0s−t). At t = 0 the object is at x = -14.0 m and has velocity v0x = 7.10 m/s.

Answers

Complete Question

A small object moves along the x-axis with acceleration ax(t) = −(0.0320m/s3)(15.0s−t)−(0.0320m/s3)(15.0s−t). At t = 0 the object is at x = -14.0 m and has velocity v0x = 7.10 m/s. What is the x-coordinate of the object when t = 10.0 s?

Answer:

The position of the object at t = 10s is  [tex]X = 38.3 \ m[/tex]

Explanation:

From the question we are told that

The acceleration along the x axis is  [tex]a_{x}t = -(0.0320\ m/s^3)(15.0 s- t)- (0.0320\ m/s^3)[/tex]

  The position of the object at t = 0 is  x = -14.0 m

  The velocity at t = 0 s is  [tex]v_{0}x = 7.10 m/s[/tex]

Generally from the equation for acceleration along x axis we have that

     [tex]a_x = \frac{dV_{x}}{dt} = -0.032 (15- t)[/tex]

=>   [tex]\int\limits {dV_{x}} \, = \int\limits {-0.032(15- t)} \, dt[/tex]

=>   [tex]V_{x} = -0.032 [15t - \frac{t^2 }{2} ]+ K_1[/tex]

At  t =0  s   and  [tex]v_{0}x = 7.10 m/s[/tex]

=>   [tex]7.10 = -0.032 [15(0) - \frac{(0)^2 }{2} ]+ K_1[/tex]

=>   [tex]K_1 = 7.10[/tex]      

So  

      [tex]\frac{dX}{dt} = -0.032 [15t - \frac{t^2 }{2} ]+ K_1[/tex]

=>  [tex]\int\limits dX = \int\limits [-0.032 [15t - \frac{t^2 }{2} ]+ K_1] }{dt}[/tex]

=>  [tex]X = -0.032 [ 15\frac{t^2}{2} - \frac{t^3 }{6} ]+ K_1t +K_2[/tex]

At  t =0  s   and   x = -14.0 m

  [tex]-14 = -0.032 [ 15\frac{0^2}{2} - \frac{0^3 }{6} ]+ K_1(0) +K_2[/tex]

=>   [tex]K_2 = -14[/tex]

So

     [tex]X = -0.032 [ 15\frac{t^2}{2} - \frac{t^3 }{6} ]+ 7.10 t -14[/tex]

At  t = 10.0 s

      [tex]X = -0.032 [ 15\frac{10^2}{2} - \frac{10^3 }{6} ]+ 7.10 (10) -14[/tex]

=>   [tex]X = 38.3 \ m[/tex]

             

     

Assuming the acceleration due to gravity on the moon is exactly one-sixth of the acceleration due to gravity on Earth, what is the weight of the object on the moon?

Answers

I have assumed a weight of 120 N on Earth.

Answer:

The object weighs 20 N on the moon

Explanation:

Weight

The weight of an object depends on the mass m of the object and the acceleration of gravity g of the place they are in.

The formula to calculate the weight is:

W = m.g

If g_e is the acceleration of gravity on Earth, and g_m is the acceleration of gravity on the moon, we know:

[tex]g_m=1/6 g_e[/tex]

Dividing by ge:

[tex]g_m/g_e = 1/6[/tex]

An object of weight We=120 N on planet Earth has a mass of:

[tex]m = 120 / g_e[/tex]

Multiplying by gm:

[tex]m.g_m=120 g_m/g_e[/tex]

Substituting the ratio of accelerations of gravity:

[tex]m.g_m=120 * 1/6[/tex]

Since m.gm is the weight on the Moon Wm:

[tex]W_m=20~N[/tex]

The object weighs 20 N on the moon

Assuming the acceleration due to gravity on the moon is exactly one-sixth of the acceleration due to gravity on Earth, the weight of the object on the moon would be one-sixth of its weight on Earth.

Knowing an object's weight on Earth and applying the ratio of the acceleration caused by gravity on the moon to that on Earth will allow us to determine an object's weight on the moon.

Assume that the object's weight on Earth is W (in newtons).

On Earth, the acceleration due to gravity = 9.8 [tex]m/s^2[/tex].

On the moon, = (1/6) * 9.8 [tex]m/s^2[/tex] = 1.6333 [tex]m/s^2[/tex]

Weight = Mass * Acceleration due to gravity

Weight on the moon = W * (1/6)

Thus, the weight of the object on the moon would be one-sixth of its weight on Earth.

For more details regarding gravity, visit:

https://brainly.com/question/31321801

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Which phrase desenbes an irregular galaxy ?
has a round shape
contains many young stars
has arms that extend from the center
Is larger than other types of galaxies

Answers

Answer:

contains many young stars

Explanation:

Irregular galaxies have no definite shape, which means that the first option is incorrect. They are definitely not round.

However, they contain many young stars because the degree of star formation is fast. They also contain old stars. Thus, the second choice is correct.

The "spiral galaxy" is the type of galaxy that has arms that extend from the center. These arms look "spiral," which influenced its name. This makes the last choice incorrect.

They are actually smaller than the other types of galaxies. This makes them prone to collisions. This makes the last choice incorrect.

Answer:

Contains many young stars

Explanation:

A box of books weighing 319 N is shoved across the floor by a force of 485 N exerted downward at an angle of 35 degres below the horizontal.a) If the coeficent of friction between the box and the floor is 0.57, how long does it take to move the box 4 meters, starting from rest?b) If If the coeficent of friction between the box and the floor is 0.75, how long does it take to move the box 4 meters, starting from rest?

Answers

Let w, n, p, and f denote the magnitudes of the 4 forces acting on the box.

• w = weight = 319 N

n = normal force

p = pushing force = 485 N

f = friction = µ n, where µ is the coefficient of static friction

The net force on the box points in the direction that the box moves, which is to the right. In particular, this means the box is vertically in equilibrium. Split up the vectors into their vertical and horizontal components, and apply Newton's second law. (I take up and right to be the positive vertical and horizontal directions, respectively.)

• vertical:

p sin(-35°) + n - w = 0

and solving for n,

- (485 N) sin(35°) + n - 319 N = 0

n ≈ 597 N

• horizontal:

p cos(-35°) - f = m a

where a is the magnitude of the net acceleration on the box. Solve for a. Since f = µ n and m = w / g (where g = 9.80 m/s² is the mag. of the acc. due to gravity) we get

p cos(35°) - µ n = (w / g) a

(485 N) cos(35°) - µ (597 N) = (319 N) / (9.80 m/s²) a

a ≈ (12.2 - 18.3 µ) m/s²

(a) If µ = 0.57, then the net acceleration on the box is

a ≈ (12.2 - 18.3 • 0.57) m/s² ≈ 1.75 m/s²

so that the time t required to move the box 4 m is

4 m = 1/2 a t ²

t ≈ √((8 m) / (1.75 m/s²))

t ≈ 2.14 s

(b) The box does not move.

If µ = 0.75, then

a = (12.2 - 18.3 • 0.75) m/s² ≈ -1.55 m/s²

but a negative acc. here means the applied acc. points *opposite* the direction of movement, thus making the box move backward which doesn't make sense. The coefficient of friction is too large for the given applied force to get the box moving. With µ = 0.75, the frictional force to overcome has mag. f ≈ 448 N. But the given push contributes a horizontal force of (485 N) cos(-35°) ≈ 397 N. This mag. needs to be increased in order to get the box moving.

(a) The time taken to move the box 4 meters is 2.14 s.

(b) The box will decelerate when the coefficient of friction is 0.75 and cannot be moved to 4 meters forward.

The given parameters;

weight of the book, W = 319 Napplied force, F = 485 Nangle of inclination, θ = 35 ⁰

The mass of the books is calculated as;

[tex]m = \frac{W}{g} \\\\m = \frac{319}{9.8} \\\\m = 32.55 \ kg[/tex]

The normal force on the box is calculated as follows;

[tex]F_n = -W - Fsin\theta\\\\F_n = -319 - (485\times sin35)\\\\F_n = -597.18 \ N[/tex]

The frictional force when the coefficient of friction is 0.57;

[tex]F_f = \mu F_n\\\\F_f = 0.57 \times -597.18\\\\F_f = -340.39 \ N[/tex]

The acceleration of the box is calculated as follows;

[tex]F cos \theta - F_f = ma\\\\(485)cos(35) \ - 340.39 = 32.55 a\\\\56.899 = 32.55a\\\\a = \frac{56.899}{32.55} \\\\a = 1.75 \ m/s^2[/tex]

The time taken to move the box 4 meters is calculated as;

[tex]s = v_0t + \frac{1}{2} at^2\\\\s = 0 + \frac{1}{2} at^2\\\\t = \sqrt{\frac{2s}{a} } \\\\t = \sqrt{\frac{2\times 4}{1.75} } \\\\t = 2.14 \ s[/tex]

(b) The frictional force when the coefficient of friction is 0.75;

[tex]F_f = \mu F_n\\\\F_f = 0.75 \times -597.18\\\\F_f = -447.885 \ N[/tex]

The acceleration of the box is calculated as follows;

[tex]F cos \theta - F_f = ma\\\\(485)cos(35) \ -447.885 = 32.55 a\\\\-50.596 = 32.55a\\\\a = \frac{-50.596}{32.55} \\\\a = -1.55\ m/s^2[/tex]

Thus, the box will decelerate when the coefficient of friction is 0.75 and cannot be moved to 4 meters forward.

Learn more here:https://brainly.com/question/21684583

Question 5 of 5
What is a definite sign of overtraining?
O A. Depression
B. Declining athletic performance
O C. A ravenous appetite
O D. Big bursts of energy
( the answer is B. i just put it on here because i didn’t see it and i got it correct :)

Answers

Answer : B. Declining athletic performance

A scientist decides to replicate an experiment completed by another scientist. Which statement describes something that would not affect the results of the replicated experiment

Answers

Hi, you've asked an incomplete question. However, I provided some explanation about the replication process that scientists do.

Explanation:

Replication in research involves carefully repeating an original experiment to see whether the same result would be arrived at as in previous research experiments.

For most scientists today, in other to avoid anything that would erroneously affect the results of the replicated experiment they usually follow the same procedures as carried by the previous researchers.

What happens when calcium reacts with chlorine?
A. Electrons become delocalized among the atoms
B. Electrons are shared between the calcium atoms and the chlorine
atoms
C. Electrons move from the chlorine atoms to the calcium atoms,
D. Electrons move from the calcium atoms to the chlorine atoms,

Answers

When calcium reacts with chlorine. Electrons move from the calcium atoms to the chlorine atoms. Option D is correct.

What is a chemical reaction?

When one or more chemicals are transformed into one or more other compounds, a chemical reaction occurs.

In an ionic compound, calcium chloride is present. To build a complete outer shell of electrons, the calcium atom loses two electrons and each chlorine atom obtains one.


When calcium combines with chlorine, it forms calcium chloride. From the calcium atoms to the chlorine atoms, electrons travel.

Hence, option D is correct.

To learn more about the chemical reaction refer to the link;

https://brainly.com/question/6876669

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