If an object with mass m strikes a wall and rebounds, what is the change in momentum if it moves from speed V0 to -V0?

• A. 2mV0 Directed to the left
• B. MV0 Directed to the left
• C. Zero
• D. MV0 Directed to the right

Answer: (A)

To understand the change in momentum when an object with mass ( m ) strikes a wall and rebounds from a speed of ( V_0 ) to ( -V_0 ), we can analyze the momentum before and after the collision.

Initially, when the object moves with a speed of ( V_0 ) towards the wall, its momentum is calculated as:

[ p_{initial} = m \cdot V_0 ]

After the collision, the object rebounds with a speed of ( -V_0 ). The momentum after the collision thus is:

[ p_{final} = m \cdot (-V_0) = -m \cdot V_0 ]

The change in momentum (( \Delta p )) is found by subtracting the initial momentum from the final momentum:

[ \Delta p = p_{final} - p_{initial} ]

[ \Delta p = (-m \cdot V_0) - (m \cdot V_0) ]

[ \Delta p = -m \cdot V_0 - m \cdot V_0 = -2m \cdot V_0 ]

This negative sign indicates that the change in momentum