Question 1

A box is being pulled up a rough incline by a rope connected to a pulley. How many forces are doing non-zero work on the box?

Accepted Answer

Three forces

Question 2

You toss a ball into the air and catch it again at the same position. While the object is in the air (from just after release to just before catch), what is the total work done by the gravitational force?

Accepted Answer

$$W = 0$$

Question 3

Suppose a mass is taken on a long and tortuous journey to the Moon, Tibet, and Amsterdam and returned to the same finish point as before. Would the total work done by gravity be the same as if it had taken a direct path?

Accepted Answer

Same

Question 4

Is kinetic friction a conservative force?

Accepted Answer

No

Question 5

The force from an ideal spring is given by which equation?

Accepted Answer

$$F = -kx$$

Question 6

A block slides from rest down a frictionless ramp and attains speed $$v at $$the bottom. To achieve speed $$2v at $$the bottom, how many times higher must the new ramp be?

Accepted Answer

4 times higher

Question 7

Is it possible for the gravitational potential energy of an object to be negative?

Accepted Answer

Yes

Question 8

A spring-loaded toy dart gun shoots a dart straight up. The dart goes up a distance $$h. $$The same dart is shot up again from the same gun, but this time the spring is compressed twice as much before firing. How far up does the dart go this time? (Assume no friction, ideal spring)

Accepted Answer

$$4h$$

Question 9

A mass oscillates on a spring. Position 0 is the unstretched position of the mass. At which point is the magnitude of the force on the mass maximum?

Accepted Answer

At the maximum displacement

Question 10

A car sits on the Earth’s surface. Both the car and the Earth are at rest. The car accelerates to a final velocity. After the car reaches $$v_{final}$$, the magnitude of the Earth’s momentum is __________ the magnitude of the car's momentum.

Accepted Answer

The same as

Question 11

Two masses, $$m$$ and $$3m$$, are initially at rest on a frictionless surface. A compressed, massless spring between them is suddenly allowed to uncompress, pushing the masses apart. After the masses are apart, the speed of $$m is ____ $$the speed of $$3m.$$

Accepted Answer

$$3$$ times the speed

Question 12

A bullet (mass $$m$$, velocity $$v) is $$fired into a wood block (mass $$M) $$initially at rest on a frictionless surface. The bullet buries itself in the wood block and then the wood block is seen to have a final velocity $$v_f. $$Was this an elastic collision?

Accepted Answer

No

Question 13

A projectile is fired with initial speed $$v_0 at an $$angle of $$45^\circ$$ above the horizontal. Assume no air resistance. During the flight, the $$x-$$component of the projectile's momentum remains constant. True or False?

Accepted Answer

True

Question 14

A ball bounces off the floor elastically as shown. The direction of change in momentum of the ball, $$\Delta p$$, is:

Accepted Answer

Straight up

Question 15

A hockey puck slides on an ice rink at $$1\ \mathrm{m/s}$$ when it slides onto a carpet. How much more kinetic energy would the puck have started with if it was initially moving $$2\ \mathrm{m/s}$$?

Accepted Answer

4 times as much

Question 16

A mass slides down a rough ramp (with friction) of height $$h. $$Its initial speed is zero. Its final speed at the bottom of the ramp is $$v. $$While the mass is descending, its kinetic energy:

Accepted Answer

Increases

Question 17

A mass slides down a rough ramp (with friction) of height $$h. $$Its initial speed is zero. Its final speed at the bottom of the ramp is $$v. $$While the mass is descending, its potential energy:

Accepted Answer

Decreases

Question 18

A child can slide (from rest) down 3 different frictionless ramps with different shapes but the same height. How does the speed of the child at the bottom of the ramps compare?

Accepted Answer

$$v_A = v_B = v_C$$

Question 19

A moving mass $$m_1 is $$approaching a stationary mass $$m_2 on a $$frictionless table. Is it possible that, as a result of the collision, all of the kinetic energy of both masses is converted to heat or other forms of energy?

Accepted Answer

No, impossible

Work, Energy, and Momentum: Study Notes for College Physics

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드