Andy took a bus and then walked from his home to downtown. For the
first 1.6 hour, the bus drove at an average speed of 15 km/h. For the
next 0.4 hours, he walked at an average speed of 4.5 km/h. What was
the average speed for the whole journey?

Answer:

150 m

Explanation:

Given,

u=5m/s

a=2m/s2

t=10s

v=?

s=?

Now,

v=u+at

=5+2×10

=5+20

=25m/s

So,

s=u+v/2×t

=5+25/2×10

=30/2×10

=15×10

=150m

Answer:

Mid-Ocean Ridges

Explanation:

The mid-ocean ridges is an underwater mountain system formed by diverging oceanic plates.

Resistance of a wire used to power clothes dryers rank comes out to be  Third. Therefore the correct answer is D.

Resistance is the obstruction of electrons in an electrically conducting material.

The mathematical relation for variation in resistance with length is given by

R = ρ*L/A

where r is resistance

ρ is the resistivity constant for

L is the length of the wire

A is an area of the cross-section for the wire

From the above relation that resistance is inversely proportional to the area of the wire keeping other parameters constant.

Resistance of a wire used to power clothes dryers rank comes out to be  Third. Therefore the correct answer is D.

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Answer:

Imp_{1-2}=5000[kg*m/s]

Explanation:

In order to solve this problem, we must use the principle of conservation of momentum, which is defined as the product of mass by Velocity.

It must be defined that the impulse after the force is applied is equal to the momentum before the impulse applied on the body.

ΣPbefore = ΣPafter

P = momentum = m*v [kg*m/s]

In this way, we will construct the following equation.

[tex](m_{1}*v_{1})+ Imp_{1-2}=(m_{1}*v_{2})[/tex]

where:

m₁ = mass of the object = 200 [kg]

v₁ = velocity of the object before the impulse = 15 [m/s]

v₂ = velocity of the object after the impulse = 40 [m/s]

Now replacing:

[tex](200*15) + Imp_{1-2} = (200*40)\\Imp_{1-2}=5000[kg*m/s][/tex]

Answer:

the gradual movement of the continents across the earth's surface through geological time.

Answer:

Continental drift is the hypothesis that the Earth's continents have moved over geologic time relatives to each other.

Answer:

C.Forced air

Explanation:

HVAC system

"By far the most common HVAC system in modern North American homes is the forced-air system that uses a furnace with a blower fan that delivers warmed air to the various rooms of the home through a network of ducts."

So can you please mark me brainliest?

Answer:

Using the range formula   S = V^2 * sin 2 theta / g

So the cannonball should travel

S = 35^2 * sin 90 / 9.8 = 125 m

Then the cannon should be placed 100 m from the wall

H = Vy t - 1/2 g t^2   height of cannonball after time t

Vy = 35 * sin 45 = 24.7 m/s     vertical speed of cannonball

Vx = 35 * cos 45 = 24.7 m/s

t = 100 m / 24,7 m/s = 4.04 sec    time for cannonball to reach wall

H = Vy t - 1/2 g t^2       height of cannonball after time t

H = 24.7 * 4.04 - 1/2 * 9.8 * 4.04^2 = 19.8 m

19.8 m - 15 m = 4.8 m     cannonball clears wall by 4.8 m

The projectile launch ratios allow to find the results on the cannonball launch questions are:

 a) The canyon is at x = 100 m from the wall.

 b) The bullet hits the wall at a height of 4.8 m above the height of the wall.

Projectile launching is an application of kinematics where there is no acceleration on the x-axis and the y-axis is gravity acceleration.

A) Indicate that the initial speed of the bullet is v = 35 m/s with an angle  θ=45º, which is the distance from the wall. The target is 25 m behind the wall, in the attachment we have a scheme of the system.

Let's find the range that is the horizontal distance for which the height is  zero.

       [tex]R = \frac{v_p^2 \ sin \ 2\theta}{g}[/tex]

Let's calculate.

       R = [tex]\frac{35^2 \ sin ( 2 45(}{9.8}[/tex]  

       R = 125 m

Therefore the canonl must be 100 m from the wall.

B) The height of the wall is y = 15m, the blah manages to pass it and by how much.

We use trigonometry to find the components of velocity.

         v₀ₓ = v₀ cos θ

         [tex]v_{oy}[/tex] = v₀ sin θ

          v₀ₓ = 34 cos 45 = 24.7 m / s

          [tex]v_{oy}[/tex] = vo sin 45 = 24.7 m / s

Let's find the time it takes for the cannonball to travel the x = 100 m

        [tex]v_x = \frac{x}{t} \\ t = \frac{x}{v_x}[/tex]

        t = [tex]\frac{100}{35 \ cos 45 }[/tex]  

        t = 4.04 s

Let's find the height for this time.

        y = [tex]v_[oy}[/tex] t - ½ g t²

Let's calculate

        y = 24.7 4.04 - ½ 9.8 4.04²

        y = 19.8 m

This height is greater than the height of the wall h = 15m, therefore the cannoball passes the wall, by a difference in height.

        Δy = y -h

        Δy = 19.8-15

        Δy = 4.8 m

In conclusion, using the projectile launch ratios we can find the results on the cannonball launch questions are:

 a) The canyon is at x = 100 m from the wall.

 b) The cannonball hits the wall at a height of 4.8m above the height of the wall.

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Answer:

The auto is moving at 38.9 m/s

The auto took 45 seconds to travel the 1033 m

Explanation:

Constant Accelerated Motion

it's a type of motion in which the velocity of an object changes uniformly in time.

The relationship between initial and final speeds is calculated by the equation:

[tex]v_f=v_o+at\qquad\qquad [1][/tex]

Where a is the constant acceleration, vo the initial speed, vf the final speed, and t the time.

Another useful equation allows us to calculate the distance x traveled by the object:

[tex]\displaystyle x=v_o.t+\frac{a.t^2}{2}\qquad\qquad [2][/tex]

(a)

Solving [1] for t and substituting into [2] we find the equation:

[tex]v_f^2=v_o^2+2ax[/tex]

This last equation will be used to solve the first part of the problem which gives the initial speed of vo=7 m/s, the uniform acceleration as a=0.71 m/s^2 and the distance traveled as x=1033 m, thus substituting:

[tex]v_f^2=7^2+2(0.71)(1033)[/tex]

[tex]v_f^2=49+1466.86=1515.86[/tex]

Thus:

[tex]v_f=\sqrt{1515.86}=38.9[/tex]

[tex]v_f=38.9 m/s[/tex]

The auto is moving at 38.9 m/s

(b)

To calculate the time, we solve [1] for t:

[tex]\displaystyle t=\frac{v_f-v_o}{a}[/tex]

[tex]\displaystyle t=\frac{38.9-7}{0.71}=45[/tex]

The auto took 45 seconds to travel the 1033 m

Answer: Second law of thermodynamics is very important because it talks about entropy and  'entropy dictates whether or not a process or a reaction is going to be spontaneous'.

Explanation:

Answer:

r = 0.5 m

Explanation:

First we find the angular speed of the ball by using its period:

ω = θ/t

For the time period:

ω = angular speed = ?

θ = angular displacement = 2π rad

t = time period = 0.5 s

Therefore,

ω = 2π rad/0.5 s

ω = 12.56 rad/s

Now, for the radius:

v = rω

r = v/ω

where,

v = linear speed = 6.29 m/s

r = radius = ?

r = (6.29 m/s)/(12.56 rad/s)

r = 0.5 m

Answer:

Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle. Regions where this process occurs are known as subduction zones.

Answer:

Heat would flow from a hot cup of coffee to a room temperature table.

Explanation:

Thermal energy will flow from a hot cup of coffee to a room temperature table.

Heat is a form of thermal energy which is the  average kinetic energy of the particles of system.

Answer:

ok will do that

Explanation:

Answer:

11.6 seconds

Explanation:

8.25/0.711=11.6

Answer:

Movement of air caused by temperature or pressure differences is wind.

Explanation:

This is due to the rotation of the Earth beneath the moving air, which causes an apparent deflection of the wind to the right in the northern hemisphere, and left in the southern hemisphere.

Answer:

Air moves because of wind

Explanation:

Air moves due to a difference of air pressure which can be caused by different temperatures. Air pressure is the push caused by the particles in the air. Hope this helps

Answer:

12m

Explanation:

Given parameters:

Distance walked westward  = 2.8m

Time of travel  = 5min

Distance walked eastward = 9.2m

Time of travel  = 10min

Unknown:

The total shopper's travel distance  = ?

Solution:

Total distance traveled is the sum of the length of path covered by a body. It is a scalar quantity.

 Total distance = distance walked westward + distance walked eastward

  Total distance  = 2.8m + 9.2m  = 12m

Answer:

3N

Explanation:

Given parameters:

Mass of toy car  = 6kg

Initial velocity = 0m/s

Final velocity  = 2m/s

Time  = 4s

Unknown:

Net force  = ?

Solution:

The net force is given by;

      Force  = mass x acceleration;

     Force  = mass  x [tex]\frac{v - u}{t}[/tex]  

 v is the final velocity

 u is the initial velocity

 t is the time taken

Now insert the parameters and solve;

  Force  = 6 x [tex]\frac{2 - 0}{4}[/tex]   = 3N

Answer:

height =20m

Explanation:

gpe=mgh

800=4×10×x

40x=800

x=20

Answer:

5m

Explanation:

Given parameters:

Work done in lifting the box  = 50J

Force applied  = 10N

Unknown:

Height of lifting the box  = ?

Solution:

Work done is the produce of force and distance;

      Work done  = Force x distance

Now to find the height;

  Work done  = Force  x height;

   50  = 10 x h

         h  = 5m

Answer:

the answer is B

Explanation:

we assume that all of these springs have tha same k , the spring constant

elastic energy for the initial system = Ep1=  [tex]\frac{kd^{2} }{2}[/tex]

for the new changed system , the spring constant = k1+k2 = k+k = 2k  , but the displacement is also reduced to 0.5 d

so Ep2 = [tex]\frac{2k(0.5d)^{2} }{2} = \frac{kd^2}{4}[/tex]

so the new total Ep stored in the new system is 1/2Ep

hope it helps

Answer:

A: wear several thin layers and a waterproof top layer

Explanation:

The most common cause of hypothermia is getting wet. Wet clothes combined with wind can pull heat away from the body very quickly. Wool is a good insulator even when it is wet, but wet cotton will bolster heat loss. When dressing for cold weather, put on several thin layers, rather than one or two heavy ones, and top with windproof and waterproof outer layers.

The best way to dress for an outdoor trip in cold weather is to wear several thin layers and a waterproof top layer, the correct option is A.

Insulation is a type of material used to create barriers to the transmission of the form of energy which either is in form of heat or electricity.

For outdoor trips in cold weather, several thin layers act as better insulating barriers for heat transfer.

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Explanation:

well the father of nation is Mahtma Gandhi.

Hello!

Topic: Dinamic

Value to calculate: Force

First, we have to calculate the aceleration, for that, lets aplicate the formula:

[tex]\boxed{a=\frac{V-Vi}{t} }[/tex]

How the final velocity is in km/h, we have to convert it on m/s, so:

m/s = km/h / 3,6

m/s = 105 / 3,6

m/s = 29,16

Then, lets replace formula according problem information:

[tex]a = \dfrac{29,16m/s-0m/s}{0,934s}[/tex]

[tex]a =31,22\ m/s^{2}[/tex]

Now, how we have the aceleration, lets applicate second law of newton for calculate the force produced:

[tex]\boxed{F=ma}[/tex]

Replace and resolve it:

F = 856 kg * 31,22 m/s^2

F = 26724,32 kg * m/s^2

Then the force is of 26724,32 kg * m/s^2

But how we know an 1 kg * m/s^2 = 1 N

Then the average of the force is of 26724,32 N  

(1) The change in momentum of race car is 89880 kg-km/h.

(2) The average force exerted on the car is of 96231.26 N.

Given data:

The mass of race car is, m = 856 kg.

The initial speed of car is, u = 0 km/h.

The final speed of car is, v = 105 km/h.

The time interval is, t = 0.934 s.

1)

The change in the impact due to average force is known as momentum change. The expression for the change in momentum is given as follows,

[tex]\Delta P = m(v-u)[/tex]

Solving as,

[tex]\Delta P = 856 \times (105-0)\\\\\Delta P = 89880 \;\rm kg.km/h[/tex]

Thus, we can conclude that the change in momentum of race car is 89880 kg-km/h.

2)

Now, use the concept of impulse-momentum which says that the impulse is equal to change in momentum. Which means,

[tex]I = \Delta P[/tex]

And impulse is,

[tex]F \times t = \Delta P\\\\F = \dfrac{\Delta P}{t}[/tex]

Solving as,

[tex]F = \dfrac{89880}{0.934}\\\\F = 96231.26 \;\rm N[/tex]

Thus, we can conclude that the average force exerted on the car is of 96231.26 N.

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Answer:

The gravitational force between the two masses is 1.668575 × 10⁻¹¹ N

Explanation:

The given parameters are;

The mass of the two asteroids having gravitational attraction, are m₁ = m₂ = m = 50,000 kg

The separation distance between their centers, r = 1,000 m

The gravitational attraction force, F, between the two masses is given as follows;

[tex]F =G\dfrac{m_{1}m_{2}}{r^{2}}[/tex]

Where;

G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²

m₁ = m₂ = m

Substituting the values gives;

[tex]F =6.67430 \times 10^{-11} \times \dfrac{50,000 \times 50,000}{1000^{2}} = 1.668575 \times 10^{-7} \ N[/tex]

The gravitational force, F, between the two masses = 1.668575 × 10⁻¹¹ N.

The gravitational force between the two identical asteroids is 1.67 × 10⁻⁷ Newton.

Given the data in the question

Since the asteroids are identical

Gravitational force; [tex]F =\ ?[/tex]

To determine the gravitational force between two identical asteroids, we use the Newton's law of universal gravitation:

[tex]F = G\frac{m_1m_2}{r^2}[/tex]

Where [tex]m_1[/tex] is mass of object 1, [tex]m_2[/tex] is mass of object 2, r is the distance between centers of the masses and G is the Gravitational constant ( [tex]6.67408 * 10^{-11} m^3/kgs^2[/tex] )

We substitute our values into the equation

[tex]F = (6.67408 * 10^{-11} m^3/kgs^2) \frac{50000kg*50000kg}{(1000m)^2} \\\\F = \frac{0.166852kgm^3/s^2}{1000000m^2}\\\\ F = 1.67 * 10^{-7}kg.m/s^2\\\\F = 1.67 * 10^{-7}N[/tex]

Therefore, the gravitational force between the two identical asteroids is 1.67 × 10⁻⁷ Newton.

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Answer:

look in internet u can find online converter and there u will get a rel answer

Explanation:

Answer:

50 kg*m/s southward

Explanation:

p=mv

 =25kg(2m/s)

 =50 kg*m/s

Answer:

The fluid friction or drag can be reduced are minimised by giving special shape called streamlined shape to the objects which Move through fluids like air or water

Answer:

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