4. Momentum and Collisions

Linear Momentum — Quiz

Test your understanding of linear momentum with 5 practice questions.

Practice Questions

Question 1

A system consists of two particles with masses $m_1$ and $m_2$. The center of mass of the system is located at a position $\vec{r}_{CM}$. If an external force $\vec{F}_{ext}$ acts on the system, which of the following expressions correctly relates the external force to the acceleration of the center of mass, $\vec{a}_{CM}$?

Question 2

A block of mass $m$ is initially at rest on a frictionless horizontal surface. A bullet of mass $m_b$ is fired horizontally into the block with an initial velocity $v_b$ and becomes embedded in it. Which of the following expressions represents the fraction of the initial kinetic energy that is lost during this inelastic collision?

Question 3

A particle of mass $m$ moves in a circular path of radius $r$ with a constant angular velocity $\omega$. Which of the following statements is true regarding its linear momentum?

Question 4

A system consists of two particles, $m_1$ and $m_2$, connected by a massless string and initially at rest on a frictionless horizontal surface. An impulse $\vec{J}$ is applied to $m_1$ in the positive x-direction. Which of the following statements is true about the motion of the center of mass of the system immediately after the impulse?

Question 5

A cannon of mass $M$ fires a cannonball of mass $m$ horizontally with a velocity $v$ relative to the ground. If the cannon is initially at rest on a frictionless surface, what is the recoil velocity of the cannon relative to the ground?