Question 1

A block of mass $m_1 = 3\ \mathrm{kg}$ slides down a frictionless half-pipe from a height $h_1 = 2\ \mathrm{m}$ and collides inelastically with a stationary block of mass $m_2 = 1.5\ \mathrm{kg}$ at the bottom. What is the velocity of the combined mass immediately after the collision?

Accepted Answer

$4.2\ \mathrm{m/s}$

Question 2

What is the total kinetic energy lost during the collision between $m_1$ and $m_2$ described above?

Accepted Answer

$19.1\ \mathrm{J}$

Question 3

Which of the following best describes the type of collision that occurs between $m_1$ and $m_2$ in the scenario above?

Accepted Answer

Completely inelastic collision

Question 4

If the height $h_1$ is doubled, what happens to the velocity of $m_1$ just before the collision?

Accepted Answer

It increases by a factor of $\sqrt{2}$

Question 5

Given $m_1$ slides down from height $h_1$ and collides with $m_2$ at rest, which equation correctly expresses the velocity of $m_1$ just before the collision?

Accepted Answer

$v_1 = \sqrt{2gh_1}$

Question 6

After the collision, what is the combined mass of the two blocks?

Accepted Answer

$4.5\ \mathrm{kg}$

Question 7

Which conservation law is used to determine the velocity of the combined mass after the collision?

Accepted Answer

Conservation of momentum

Question 8

If friction were present on the half-pipe, how would the final velocity of the combined mass after collision be affected?

Accepted Answer

It would decrease

Question 9

Suppose $m_2$ was moving toward $m_1$ with velocity $v_2$ before the collision. Which equation would you use to find the final velocity after a completely inelastic collision?

Accepted Answer

$v_f = \frac{m_1 v_1 + m_2 v_2}{m_1 + m_2}$

Question 10

If the collision were elastic instead of completely inelastic, what would be true about the kinetic energy before and after the collision?

Accepted Answer

Kinetic energy would be conserved

Question 11

In the scenario, why is air resistance neglected in the calculations?

Accepted Answer

To simplify the problem and focus on conservation laws

Question 12

If the blocks did not stick together after the collision, which type of collision would it be?

Accepted Answer

Partially inelastic

Question 13

What is the initial potential energy of $m_1$ before it slides down the half-pipe?

Accepted Answer

$U = m_1 g h_1$

Question 14

If the combined mass after collision moves up another frictionless ramp, what principle would you use to determine its maximum height?

Accepted Answer

Conservation of energy

Question 15

Which of the following is a correct statement about completely inelastic collisions?

Accepted Answer

The colliding objects stick together after the collision

Question 16

If $m_1$ was released from a greater height, what would happen to the kinetic energy lost in the collision?

Accepted Answer

It would increase

Question 17

Which equation correctly calculates the kinetic energy lost in the collision?

Accepted Answer

$\Delta KE = \frac{1}{2}(m_1 + m_2)v_f^2 - \frac{1}{2}m_1 v_1^2$

Question 18

If the collision occurred on a rough surface, which of the following would NOT be true?

Accepted Answer

Mechanical energy would be conserved

Question 19

A student claims that momentum is not conserved in inelastic collisions. Is this correct?

Accepted Answer

No, momentum is always conserved in collisions (if no external force acts)

Question 20

If $m_1$ and $m_2$ were equal, what would be the velocity of the combined mass after the collision, given $m_1$ slides down from height $h_1$?

Accepted Answer

$v_f = \frac{v_1}{2}$

Collisions and Conservation Laws in Physics: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards