Physics Work and Energy Quiz

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What is the formula for calculating work when force and displacement are in the same direction?

W = F * S * cos 90°
W = - F * S
W = F * S (correct)
W = F * S * cos θ

Negative work occurs when the force and displacement are moving in the same direction.

False (B)

What is the value of work done when a force of 15N moves an object a distance of 5m in the direction of the force?

75 J

If the force is perpendicular to the displacement, then the work done is ______.

0 Signup and view all the answers

Match the type of work to its condition:

Positive Work = 0° ≤ θ < 90° Negative Work = 90° < θ ≤ 180° Zero Work = θ = 90° or Displacement is 0 Signup and view all the answers

What is the formula for calculating kinetic energy?

$KE = rac{1}{2} mv^2$ (B) Signup and view all the answers

Kinetic energy is a vector quantity.

False (B) Signup and view all the answers

What happens to an object's kinetic energy when it accelerates?

It increases. Signup and view all the answers

The energy possessed by an object due to its motion is called ______.

kinetic energy Signup and view all the answers

What is the work done by the porter lifting the suitcase?

392 J (D) Signup and view all the answers

Energy is measured in Joules.

True (A) Signup and view all the answers

Match the following variables with their meanings in the kinetic energy formula:

KE = Kinetic energy of the object m = Mass of the object v = Velocity of the object 1/2 = A constant factor in kinetic energy calculation Signup and view all the answers

What is the gravitational force acting on the suitcase lifted by the porter?

196 N Signup and view all the answers

What is the formula to calculate work when force and displacement are at an angle?

$W = F imes S imes cos heta$ (B) Signup and view all the answers

Work is done when a force is applied but there is no displacement of the object.

False (B) Signup and view all the answers

When a spring is compressed or stretched, the work done by the spring is ___ when the spring is compressed.

negative Signup and view all the answers

Match the following terms with their definitions:

Work = Force applied over a distance Gravitational Force = Attraction between masses Spring Force = Force by a compressed or stretched spring Energy = Ability to do work Signup and view all the answers

What is the unit of work in the International System of Units (S.I.)?

Joule Signup and view all the answers

The value of gravitational acceleration (g) is approximately _____ m/s².

9.8 Signup and view all the answers

Match the following angles with their corresponding cosine values:

0° = 1 90° = 0 180° = -1 45° = 0.707 Signup and view all the answers

What is the initial kinetic energy of a body of mass 10 kg moving at a velocity of 5 m/s?

125 Joules (C) Signup and view all the answers

Doubling the velocity results in quadrupling the kinetic energy.

True (A) Signup and view all the answers

What is the mass of the body in the problem?

10 kg Signup and view all the answers

The final kinetic energy when the velocity is doubled to 10 m/s is ___ Joules.

500 Signup and view all the answers

Match the following velocities with their respective kinetic energies:

5 m/s = 125 Joules 10 m/s = 500 Joules Signup and view all the answers

Increasing the mass of an object has no effect on its kinetic energy if the velocity remains constant.

False (B) Signup and view all the answers

What is the effect of a decrease in velocity on the kinetic energy of an object?

The kinetic energy decreases. Signup and view all the answers

The work done on an object can be calculated as the change in _____.

energy Signup and view all the answers

Match the following problems with their corresponding calculations:

Bullet problem = Calculating kinetic energy from bullet velocity Car problem = Calculating work done during braking Truck problem = Comparing kinetic energy between truck speeds Force and mass = Determining braking forces based on mass Signup and view all the answers

What is the SI unit of power?

Watt (B) Signup and view all the answers

Kinetic Energy (KE) transforms into Potential Energy (PE) when an object is thrown upwards.

True (A) Signup and view all the answers

What is the formula for power?

P = W/t or P = E/t Signup and view all the answers

1 Watt is equal to ______ Joule of work done in 1 second.

1 Signup and view all the answers

Match the following energy transformations with their descriptions:

Light = Electric --> Solar cell/panel Sound = Electric --> Microphone Electric = Sound --> Speaker Kinetic Energy = Potential Energy when thrown upwards Signup and view all the answers

What is the work required to bring the bullet to rest with a mass of 0.05 kg and an initial velocity of 200 m/s?

1000 J (D) Signup and view all the answers

Gravitational potential energy is the energy an object has due to its speed.

False (B) Signup and view all the answers

What is the formula for potential energy?

U = mgh Signup and view all the answers

The work done by the brakes on a truck with a mass of 2000 kg, initially traveling at 15 m/s and slowing down to 5 m/s, is _____ J.

200000 Signup and view all the answers

What is the potential energy of an object with a mass of 5 kg raised to a height of 3 meters? (Use $g = 9.81rac{m}{s^2}$)

147.15 J (C) Signup and view all the answers

What does the equation E = mgh represent?

Gravitational potential energy (B) Signup and view all the answers

The potential energy of an object depends on the path taken to reach its height.

False (B) Signup and view all the answers

The final calculated power value from the given calculations is 3820W.

True (A) Signup and view all the answers

What are the two forms of energy produced when a fuel undergoes combustion?

Light and Heat Signup and view all the answers

What is the result of the calculation when using the values 200 kg, 9.8 m/s², and a height of 10 m in the formula for gravitational potential energy?

-19600 J Signup and view all the answers

The law of conservation of energy states that mass can neither be ______ nor destroyed.

created Signup and view all the answers

In the equation P = E/t, the variable 't' represents _____ time.

time Signup and view all the answers

Match the following energy conversions with their processes:

Photosynthesis = Light → Chemical Burning of fuel = Chemical → Heat Electric heater = Electric → Heat Incandescent bulb = Electric → Light Signup and view all the answers

Match the following parameters with their definitions:

E = Energy measured in Joules P = Power measured in Watts m = Mass measured in kilograms g = Acceleration due to gravity, approx. 9.8 m/s² Signup and view all the answers

What is work?

Work is done when a force causes an object to move in the direction of the applied force.

How to calculate work

Work is calculated by multiplying the force applied by the distance the object moves.