Question

A ball of mass 0.5 kg moving horizontally at \( 10\, \text{ms}^{-1} \) strikes a vertical wall and rebounds with speed \( V \). The change in linear momentum is 8.0 kg·m/s. Find the magnitude of \( V \).

• A. 6.0 m/s
• B. 9.0 m/s
• C. 26.0 m/s
• D. 13.0 m/s

Hint:

Change in momentum = Final momentum (opposite) + Initial momentum (when direction reverses).

Answer 1

The Correct Option is A

Initial momentum = \( 0.5 \cdot 10 = 5 \, \text{kg·m/s} \) (right)
Final momentum = \( 0.5 \cdot V \) (left)
Change in momentum = \( 0.5 \cdot V + 5 = 8 \)
\[ \Rightarrow 0.5V = 3 \Rightarrow V = 6 \, \text{m/s} \]