Question 1

Which equation best represents the work-energy theorem as discussed in class?

Accepted Answer

$$W_{total} = \Delta KE$$

Question 2

A 1 kg ball is dropped from a height of 100 m. What is its gravitational potential energy at the top, assuming $$g = 9.8 \ m/s^2$?

Accepted Answer

$$980 \ J$$

Question 3

Which of the following statements about energy is correct?

Accepted Answer

Energy is the capacity to do work.

Question 4

According to Noether's theorem, conservation of energy is a result of which physical symmetry?

Accepted Answer

Time-invariance symmetry

Question 5

A moving car comes to a stop due to friction. What is the sign of the total work done by friction?

Accepted Answer

Negative

Question 6

If the initial speed of a car is doubled, how does the stopping distance change, assuming the same friction force?

Accepted Answer

It is quadrupled.

Question 7

Which of the following is an example of a conservative force?

Accepted Answer

Gravitational force

Question 8

What is the formula for gravitational potential energy near the surface of the Earth?

Accepted Answer

$$U_{grav} = mgy$$

Question 9

A 1 kg ball is dropped from 100 m. Neglecting air resistance, what is its kinetic energy just before hitting the ground?

Accepted Answer

$$980 \ J$$

Question 10

Which of the following best describes mechanical energy?

Accepted Answer

Mechanical energy is the sum of kinetic and potential energy.

Question 11

A crate slides across a factory floor and stops due to friction. Which equation most directly determines the stopping distance?

Accepted Answer

$$d = \frac{1}{2} \frac{mv^2$}{F}$$

Question 12

If a drawn bow has 50 J of potential energy and the arrow leaves with 40 J of kinetic energy, what happens to the remaining energy?

Accepted Answer

10 J goes to warming the bow.

Question 13

Which of the following is true about the work done by a conservative force?

Accepted Answer

It is independent of the path taken.

Question 14

When only conservative forces act on an object, what can be said about the total mechanical energy?

Accepted Answer

It remains constant.

Question 15

A ball is thrown straight upward. At the top of its path, which statement is true?

Accepted Answer

Kinetic energy is zero and potential energy is maximum.

Question 16

Which of the following is NOT a unit of energy?

Accepted Answer

Newton

Question 17

Which force does the work to stop a moving car when brakes are applied?

Accepted Answer

Friction force from the brakes

Question 18

If the work done on an object by a force is positive, what happens to the object's energy?

Accepted Answer

The force adds energy to the object.

Question 19

Which of the following is a non-conservative force?

Accepted Answer

Friction

Question 20

Which scenario best illustrates the conversion of kinetic energy to potential energy?

Accepted Answer

A ball thrown upward slows down as it rises.

Work, Energy, and Conservation of Energy: Study Notes

스터디 가이드 - 연습 문제