Energy and Work: Master the Fundamentals of Classical Mechanics

Question 1

Which of the following is the internationally accepted unit of energy?

Accepted Answer

Joule

Answer

Newton

Answer

Watt

Answer

Kelvin

Question 2

A ball is thrown vertically upwards. At its peak height, what is the relationship between its kinetic and potential energies?

Accepted Answer

Kinetic energy is zero and potential energy is maximum.

Answer

Potential energy is zero and kinetic energy is maximum.

Answer

Both kinetic and potential energy are zero.

Answer

Both kinetic and potential energy are maximum.

Question 3

Which of the following is NOT classified as a type of mechanical energy?

Accepted Answer

Electrical energy

Answer

Kinetic energy

Answer

Potential energy

Answer

Elastic energy

Question 4

A car maintains a constant velocity. Which of the following statements about the work done on the car is accurate?

Accepted Answer

The net work done on the car is zero.

Answer

The net work done on the car is positive.

Answer

The net work done on the car is negative.

Answer

The work done by the engine equals the work done by friction.

Question 5

The work done by a force acting on an object is best described by which of the following?

Accepted Answer

The product of the force and the displacement in the direction of the force.

Answer

The product of the force and the displacement perpendicular to the force.

Answer

The product of the force and the total distance moved by the object.

Answer

Independent of the distance moved by the object.

Question 6

Which type of potential energy relies on an object's vertical height compared to a reference point?

Accepted Answer

Gravitational potential energy

Answer

Elastic potential energy

Answer

Chemical potential energy

Answer

Electrical potential energy

Question 7

Which of the following is the formula for kinetic energy?

Accepted Answer

E = 1/2 mv^2

Answer

E = mc^2

Answer

E = Fd

Answer

E = mgh

Question 8

Which of the following is NOT a type of potential energy?

Accepted Answer

Magnetic potential energy

Answer

Gravitational potential energy

Answer

Elastic potential energy

Answer

Chemical potential energy

Question 9

What happens to the kinetic and potential energies of a block sliding down a frictionless inclined plane?

Accepted Answer

Kinetic energy increases, potential energy decreases.

Answer

Potential energy increases, kinetic energy decreases.

Answer

Both kinetic and potential energies remain constant.

Answer

Kinetic energy decreases, potential energy increases.

Question 10

A roller coaster car is at the top of a hill. Which statement is accurate?

Accepted Answer

Potential energy is maximum, kinetic energy is minimum.

Answer

Kinetic energy is maximum, potential energy is minimum.

Answer

Both potential and kinetic energies are maximum.

Answer

Both potential and kinetic energies are minimum.

Question 11

Which force is conservative?

Accepted Answer

Gravity

Answer

Friction

Answer

Tension

Answer

Air resistance

Question 12

When a spring is stretched, what happens to its energies?

Accepted Answer

Potential energy increases.

Answer

Kinetic energy increases.

Answer

Both kinetic and potential energies increase.

Answer

Neither kinetic nor potential energy changes.

Question 13

Which of the following is the SI unit of energy?

Accepted Answer

Joule

Answer

Meter

Answer

Second

Answer

Kilogram

Question 14

A ball of mass 2 kg is thrown vertically upwards with a velocity of 10 m/s. Calculate its kinetic energy at the highest point of its trajectory.

Accepted Answer

0 J

Answer

50 J

Answer

100 J

Answer

200 J

Question 15

A spring is compressed by a force of 100 N over a distance of 0.1 m. Determine the potential energy stored in the spring.

Accepted Answer

5 J

Answer

10 J

Answer

50 J

Answer

100 J

Question 16

Which of the following is a form of mechanical energy?

Accepted Answer

Potential energy

Answer

Heat

Answer

Light

Answer

Electrical energy

Question 17

The power of an engine is measured in:

Accepted Answer

Watts

Answer

Joules

Answer

Horsepower

Answer

Newtons

Question 18

A ball of mass m is thrown vertically upwards with an initial velocity u. What is the maximum height reached by the ball?

Accepted Answer

u^2 / (2g)

Answer

(u^2)g

Answer

u^2 / (g)

Answer

2u^2 / g

Question 19

Which of the following statements about potential energy is true?

Accepted Answer

Potential energy can be negative.

Answer

Potential energy is measured in Newtons.

Answer

Potential energy is a non-conservative force.

Answer

Potential energy depends on the momentum of an object.

Question 20

A spring of spring constant k is stretched by a distance x. The work done in stretching the spring is:

Accepted Answer

1/2 kx^2

Answer

kx^3

Answer

kx

Answer

1/4 kx^2

Question 21

Which of the following is a form of energy?

Accepted Answer

Potential energy

Answer

Force

Answer

Acceleration

Answer

Velocity

Question 22

A block of mass m slides down a frictionless inclined plane of length l and height h. What is the velocity of the block at the bottom of the plane?

Accepted Answer

sqrt(2gh)

Answer

gh

Answer

1/2 gh

Answer

2gh

Question 23

A pendulum of mass m and length l is released from a height h. What is the potential energy of the pendulum at the highest point?

Accepted Answer

mgh

Answer

g/mh

Answer

mh/g

Answer

mg/h