Answer:
Covalent Bond
Explanation:
i took the test , mark me brainliest.
Answer: Electrical
Explanation: Atoms are tied together by electrical bonding forces.
Name the part of the human eye which acts as a protective layer for the eye
Answer:
Cornea
Explanation:
Cornea protects outer layer of the eye.
Which two substances have no fixed shape and no fixed volume?
A: crystalline solid and noncrystalline solid
B: noncrystalline solid and liquid
C: plasma and liquid
D: gas and plasma
Answer:
D: gas and plasma
Explanation:
It takes 3.8 x 10^-5 for a pulse of the radio waves from a radar to reach a plane and bounce back. How far is the plane from the radar?
Answer: 11400 m
Explanation:
Given:
t = 3.8 x 10^-5 s
v = 3 x 10^8 m/s
d = ?
Formula:
d = vt
= (3.8 x 10^-5 s)(3 x 10^8 m/s)
= 11400 m
hope this helps :)
The uniform movement allows to find the results for the distance from the radar to the plane is: 5.7 10³ m or 5.7 km
Kinematics studies the motion of objects looking for relationships between position, velocity and acceleration, in the special case that the acceleration is zero is called uniform motion and is described by the expression
[tex]v = \frac{d}{t}[/tex]
d = v t
Where v is the velocity, d the displacement and t the time.
Radar waves are electromagnetic waves with constant velocity
v = 3 10⁸ m/s
They indicate that the time of the waves to go to the plane and return is 3.8 10⁻⁵ s, therefore if the speed is constant, the time to reach the plane is half of the total time.
t = [tex]\frac{t_{total} }{ 2}[/tex]
t = [tex]\frac{3.8 \ 10^{-5}}{2}[/tex]
t = 1.9 10⁻⁵ s
Let's calculate
d = 3 10⁸ 1.9 10⁻⁵
d = 5.7 10³
In conclusion with the uniform movement we can find the results for the distance from the radar to the plane is: 5.7 10³ m or 5.7 km
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what phase changes take place when you are adding energy to the substance
Answer:
During a phase change, a substance undergoes transition to a higher energy state when heat is added, or to a lower energy state when heat is removed. Heat is added to a substance during melting and vaporization. Latent heat is released by a substance during condensation and freezing. Explanation:
A student creates an electromagnetic wave and then reverses the direction of the current. Which of the following will happen to the magnetic field?
Answer:
I believe the electromagnetic field should be reversed.
Explanation:
When a student creates an electromagnetic wave and then reverses the direction of the current, the direction of the magnetic field will be reversed.
What is an Electromagnetic wave?An electromagnetic wave may be defined as a type of wave that is significantly created as a result of vibrations between an electric field and a magnetic field. These waves are composed of oscillating magnetic and electric fields.
According to the context of this question, when an individual is constructing an electromagnetic wave and then reverses the direction of the current, it will eventually affect the direction of the magnetic field in the same direction with respect to the current. So, if the direction of the current is reversed, the direction of the magnetic field would also be reversed.
Therefore, when a student creates an electromagnetic wave and then reverses the direction of the current, the direction of the magnetic field will be reversed.
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Your question seems incomplete. The most probable complete question is as follows:
A student creates an electromagnetic wave and then reverses the direction of the current. Which of the following will happen to the magnetic field?
The direction of the magnetic field will be reversed. The magnetic field will expand.The magnetic field would be canceled out and disappear.The magnetic field will cause the voltage of the battery to be reduced.A boy whirls a ball on a string in a horizontal circle of radius 1 m. How many revolutions per minute must the ball make if its acceleration towards the center of the circle is to have the same magnitude as the acceleration due to gravity
Answer:
Nearest, the revolutions per minute will be 29.
Explanation:
Given that,
Radius of circle = 1 m
Acceleration a =g
We know that,
Angular frequency is defined as,
[tex]\omega=2\pi n[/tex]
Where, n = number of revolutions in one second
We need to calculate the revolutions in one second
Using formula of centripetal acceleration
[tex]a=\omega^2r[/tex]
Put the value of a and ω
[tex]g=(2\pi n)^2r[/tex]
[tex]n=\sqrt{\dfrac{g}{r}}\times\dfrac{1}{2\pi}[/tex]
Put the value into the formula
[tex]n=\sqrt{\dfrac{9.8}{1}}\times\dfrac{1}{2\pi}[/tex]
[tex]n=0.49[/tex]
We need to calculate the revolutions per minute
Using value for the revolutions per minute
[tex]n=0.49\times60[/tex]
[tex]n=29.4[/tex]
Hence, Nearest, the revolutions per minute will be 29.
Luck walked to a store that is 250m away and it took him 50secs while Layne walked to the mall that is 1000m away and took her 200s to do. What do they have in common?
A. Average speed
B. Acceleration
C. Displacement
D.mass
Answer:
Average speed
Explanation:
250/50=5
1000/20=5
1. What quantity of heat is required to raise?
the temperature of 450 grams of water
from 35°C to 85°C?
capacity of water is 4.18 J/g °C.
Answer: Calculate the energy required in joules to raise the temperature of 450 grams of water from 15°C to 85°C? (The specific heat capacity of water is 4.18 J/g/°C)
Explanation:
The quantity of heat is required to raise the temperature of of water is 94050 joule.
What is law of conservation of energy?Energy cannot be created or destroyed, according to the law of conservation of energy. However, it is capable of change from one form to another. An isolated system's total energy is constant regardless of the types of energy present.
The law of energy conservation is adhered to by all energy forms. The law of conservation of energy essentially says that the total energy of the system is conserved in a closed system, also known as an isolated system.
Mass of water: m = 450 grams
Initial temperature of water = 35° C
Final temperature of water = 85° C
Capacity of water is 4.18 J/g °C.
Hence, the quantity of heat is required to raise = mass × Capacity × raise in temperature
= 450 × 4.18 × (85 - 35) joule
= 94050 joule.
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How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns
Complete Question
How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns.
The output from the secondary coil is 12 V
Answer:
The value is [tex]N_s = 21 \ turns [/tex]
Explanation:
From the equation we are told that
The input voltage is [tex]V_{in} = 120 \ V[/tex]
The number of turns of the primary coil is [tex]N_p = 210 \ turn[/tex]
The output from the secondary is [tex]V_o = 12V[/tex]
From the transformer equation
[tex]\frac{N_p}{V_{in}} =\frac{N_s}{V_o}[/tex]
Here [tex]N_s[/tex] is the number of turns in the secondary coil
=> [tex]N_s = \frac{N_p}{V_{in}} * V_s[/tex]
=>[tex]N_s = \frac{210}{120} * 12[/tex]
=>[tex]N_s = 21 \ turns [/tex]
distance is constant and time increseas
Will Speed increase or decrease?
Answer:
The speed will be decrease
Which factor affects the amount of runoff that occurs in an area?
land use
the water table
the saturation zone
amount of nutrients in soil
Answer:
A. land use
Explanation:
Answer:
a
Explanation:
Help me Please!!!!!!!
What is the volume of an object if it has a mass of 10 grams and a density of 87 g/ml
Answer:
The answer is 0.115 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 10 g
density = 87 g/ml
We have
[tex]volume = \frac{10}{87} \\ = 0.114942528...[/tex]
We have the final answer as
0.115 mLHope this helps you
How much energy is used by a 1000 W microwave that operates for 5
minutes?
Answer:
300000 Joules
Explanation:
Recall that the unit Watts is Joules per second, derived from the quotient of energy per unite of time. Therefore, to calculate the energy used on the given time, we need to multiply the power used (1000 W) times the time used. Then we need to express the 5 minutes in seconds to get our answer in Joules:
5 minutes = 5 * 60 seconds = 300 seconds
Final energy calculation gives:
E = 1000 W * 300 sec= 300000 Joules
Which object will require the greatest amount of force to change its motion?
A. A 148 kg object moving 131 m/s
B. A 153 kg object moving 127 m/s
C. A 160 kg object moving 126 m/s
O D. A 162 kg object moving 124 m/s
Answer: D 160kg object moving 126 m/s
Explanation:
An object having a mass of 162 kg and moving with a velocity of 124 m/sec will require the greatest amount of force to change its motion. The correct option is D.
What is force?Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
If the object has to stop, the final velocity must be zero. If the time is constant, the amount of force only depends on the mass and the velocity at which the body is moving.
The amount of force on the object depends on the momentum of the body.
The momentum of the body is;
P = mv
Object D will require the greatest amount of force to change its motion. Because the momentum of the body for option D is the greatest.
Hence, the correct option is D.
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How do I proton and and electron compared
A block of mass 20 kg is being pulled by a force F on a rough horizontal surface. If the
coefficient of friction is 0.4, calculate
a) the normal force, N
b) the static frictional force, f
c) the minimum force required for the block to move with uniform speed
A vector of components (−23, −22) is multiplied by the scalar value of −6. What is the magnitude and direction of the resultant vector?
Answer:
(1,)
Explanation:
Answer:
magnitude: 21.6; direction: 33.7°
Explanation:
Man A (70kg) and Man B (90kg) are hanging motionless from a platform at rest. What is the tension TA in the top rope if the platform accelerates upward at a constant rate of 2 m/s2
Answer:
The tension in the upper rope (top rope), T1 = 1,888 N
Explanation:
The Parameters that were given:
Mass A, M1 = 70kg
Mass B. M2 = 90kg
acceleration, a = 2 m/s2
Assume the rope doesn't have mass, acceleration due to gravity, g
= 9.8 m/s2
The tension, T in a platform = m (a + g)
Then the tension, T1 in the upper rope = m1 (a + g) + T2
Where T2 = Tension in the lower rope
First, we calculate T2
Since the platform accelerates upward the acceleration would be positive
T2 = m2 (a + g)
T2 = 90kg ( 2 m/s2 + 9.8 m/s2)
T2 = 1,062N
To calculate the tension T1,
T1 = m1 (a + g) + T2
= 70kg (2 m/s2 + 9.8 m/s2) + 1062N
T1 = 1,888 N
A bird is flying in a room with a velocity field of . Calculate the temperature change that the bird feels after 9 seconds of flight, as it flies through x
Complete Question
The complete question is shown on the first uploaded image
Answer:
The temperature change is [tex]\frac{dT}{dt} = 1.016 ^oC/m[/tex]
Explanation:
From the question we are told that
The velocity field with which the bird is flying is [tex]\vec V = (u, v, w)= 0.6x + 0.2t - 1.4 \ m/s[/tex]
The temperature of the room is [tex]T(x, y, u) = 400 -0.4y -0.6z-0.2(5 - x)^2 \ ^o C[/tex]
The time considered is t = 10 \ seconds
The distance that the bird flew is x = 1 m
Given that the bird is inside the room then the temperature of the room is equal to the temperature of the bird
Generally the change in the bird temperature with time is mathematically represented as
[tex]\frac{dT}{dt} = -0.4 \frac{dy}{dt} -0.6\frac{dz}{dt} -0.2[2 * (5-x)] [-\frac{dx}{dt} ][/tex]
Here the negative sign in [tex]\frac{dx}{dt}[/tex] is because of the negative sign that is attached to x in the equation
So
[tex]\frac{dT}{dt} = -0.4v_y -0.6v_z -0.2[2 * (5-x)][ -v_x][/tex]
From the given equation of velocity field
[tex]v_x = 0.6x[/tex]
[tex]v_y = 0.2t[/tex]
[tex]v_z = -1.4 [/tex]
So
[tex]\frac{dT}{dt} = -0.4[0.2t] -0.6[-1.4] -0.2[2 * (5-x)][ -[0.6x]][/tex]
substituting the given values of x and t
[tex]\frac{dT}{dt} = -0.4[0.2(10)] -0.6[-1.4] -0.2[2 * (5-1)][ -[0.61]][/tex]
[tex]\frac{dT}{dt} = -0.8 +0.84 + 0.976[/tex]
[tex]\frac{dT}{dt} = 1.016 ^oC/m[/tex]
Explain why the bottom of the ship is deeper below the surface of the sea
when the ship is fully loaded with cargo
Answer:
uhh more mass = more pull by gravity = ship go sinky more
Explanation:
At a certain instant, a proton is moving in the positive x direction through a magnetic field in the negative z direction. What is the direction of the magnetic force exerted on the proton
Answer: positive y direction
Explanation:
we know that direction of velocity is in +x direction
now the magnetic force is in negative z direction
therefore the magnetic force , F = q × ( v × B)
F = ( i × [ - k ] ) direction
F = j direction
so the direction of the magnetic force on the proton is positive y direction.
Find the linear velocity of a point moving with uniform circular motion, if the point covers a distance s in the given amount of time t. s
Answer:
The linear velocity is represented by the following expression: [tex]v = \frac{s}{t}[/tex]
Explanation:
From Rotation Physics we know that linear velocity of a point moving with uniform circular motion is:
[tex]v = r\cdot \omega[/tex] (Eq. 1)
Where:
[tex]r[/tex] - Radius of rotation of the particle, measured in meters.
[tex]\omega[/tex] - Angular velocity, measured in radians per second.
[tex]v[/tex] - Linear velocity of the point, measured in meters per second.
But we know that angular velocity is also equal to:
[tex]\omega = \frac{\theta}{t}[/tex] (Eq. 2)
Where:
[tex]\theta[/tex] - Angular displacement, measured in radians.
[tex]t[/tex] - Time, measured in seconds.
By applying (Eq. 2) in (Eq. 1) we get that:
[tex]v = \frac{r\cdot \theta}{t}[/tex] (Eq. 3)
From Geometry we must remember that circular arc ([tex]s[/tex]), measured in meters, is represented by:
[tex]s = r\cdot \theta[/tex]
[tex]v = \frac{s}{t}[/tex]
The linear velocity is represented by the following expression: [tex]v = \frac{s}{t}[/tex]
A cannonball is fired horizontally from a 10 m high cliff at 20 m/s. How long will the cannonball be in the air? How far away will the cannonball strike the ground?
Answe ¡Buenos días! –
#3 ¡Buenas tardes! –
#4 ¡Bienvenid
Calculate the effective value of g, the acceleration of gravity, at 6700 m , above the Earth's surface. g
Answer:
The effective value of g at 6700 m above the Earth's surface is 9.79 m/s².
Explanation:
The value of g can be found using the following equation:
[tex] F = \frac{GmM}{r^{2}} [/tex]
[tex] ma = \frac{GmM}{r^{2}} [/tex]
[tex] a = \frac{GM}{r^{2}} [/tex]
Where:
a is the acceleration of gravity = g
G: is the gravitational constant = 6.67x10⁻¹¹ m³/(kg.s²)
M: is the Earth's mass = 5.97x10²⁴ kg
r: is the Earth's radius = 6371 km
Since we need to find g at 6700 m, the total distance is:
[tex] r_{T} = 6371000 m + 6700 m = 6377700 m [/tex]
Now, the value of g is:
[tex] a = \frac{GM}{r_{T}^{2}} = \frac{6.67\cdot 10^{-11} m^{3}/(kg*s^{2})*5.97 \cdot 10^{24} kg}{(6377700 m)^{2}} = 9.79 m/s^{2} [/tex]
Therefore, the effective value of g at 6700 m above the Earth's surface is 9.79 m/s².
I hope it helps you!
A crane uses a single cable to lower a steel girder into place. The girder moves with constant speed. The cable tension does work WT and gravity does work WG. Which statement is true
Explanation:
Work done by a force is given by :
[tex]W=Fd\cos\theta[/tex]
Where
F is force, d is displacement and [tex]\theta[/tex] is the angle between F and d.
In this problem, a crane is moving in downward direction, the force gravity is in downward direction and the tension is in upward direction.
We know that if force and displacement is in same direction, work is positive while if force and displacement is in oposite direction, work is negative.
I would mean that, [tex]W_g[/tex] is positive, because gravity is parallel to the displacement and [tex]W_t[/tex] is negative, because the tension is opposite to the displacement.
A person following a liberal ideology would likely approve of
please help asap
You jog for 55 minutes and reach a park that is 4.8 km away. What was your speed?
Answer: 59.8 or 299/5- 55 x 4.8=264
Explanation:
Or if you wish to multiply it then the answer is above with the addition version.
Hope this helped :)
Victor has 100 trading cards, each with a distinct power level between 101 and 200 inclusive. Whenever he heads out, he always randomly selects 21 cards to bring with him just in case he meets a fellow collector. Prove that no matter which 21 cards he brings, Victor will always be able to select 4 of those cards that exhibit the following property:
Let the average power level of all 4 cards bep. The cards can be split into two pairs, each of which also has an average power level of p.
Answer:
Victor will always be able to select 4 of those cards with the following property
Explanation:
Number of trading cards = 100
victor selects 21 cards
let the 4 cards be labelled : A,B,C and D
The average power level of : A,B,C,D = ( A + B + C + D )/ 4 = P
let the two pairs be : ( A + B ) and ( C + D )
note: average power of each pair = P and this shows that
( A + B ) = ( C + D ) for Victor to select 4 cards out of the 21 cards that exhibit the same property
we have to check out the possible choices of two cards out of 21 cards yield distinct sums.
= C(21,2)=(21x20)/2 = 210.
from the question the number of distinct sums that can be created using 101 through 200 is < 210 .
hence it is impossible to get 210 distinct sums therefore Victor will always be able to select 4 of those cards
2. If a car is accelerating under a net force of 3674 N, what force must the
brakes exert to cause the car to have constant velocity?*
Answer:
I don't do physics but I think the answer would be -3674
Explanation:
Newton's 2 law of motion