Question

16 the diagram below shows two balls of equal mass. ball x is moving toward ball y at 2 m/s and ball y is at rest. when ball x collides with ball y, ball x stops moving. which of the following best describes the motion of ball y after the collision? a it will remain at rest. b it will move to the right at 0.5 m/s. c it will move to the right 2 m/s. d it will move to the right at 4 m/s.

Explanation:

Step1: Apply conservation of momentum

The formula for conservation of momentum is $m_1u_1 + m_2u_2=m_1v_1 + m_2v_2$. Let the mass of each ball be $m$, the initial velocity of ball $X$ be $u_1 = 2$ m/s, initial velocity of ball $Y$ be $u_2=0$ m/s, final velocity of ball $X$ be $v_1 = 0$ m/s, and final velocity of ball $Y$ be $v_2$. Substituting into the formula: $m\times2+m\times0=m\times0 + m\times v_2$.

Step2: Solve for $v_2$

Simplifying the left - hand side of the equation gives $2m$, and the right - hand side is $mv_2$. Since $2m=mv_2$ and $m
eq0$ (as the balls have non - zero mass), we can divide both sides by $m$ to get $v_2 = 2$ m/s.

Answer:

C. It will move to the right 2 m/s.