## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

The speed of the truck relative to the ground is $30.0~m/s$
Let $v_{b,g}$ be the velocity of the ball relative to the ground. Let $v_{b,t}$ be the velocity of the ball relative to the truck. Let $v_{t,g}$ be the velocity of the truck relative to the ground. We can find the velocity of the truck relative to the round: $v_{b,g} = v_{b,t}+ v_{t,g}$ $v_{t,g} = v_{b,g} - v_{b,t}$ $v_{t,g} = (-10.0~m/s) - (-40.0~m/s)$ $v_{t,g} = 30.0~m/s$ The speed of the truck relative to the ground is $30.0~m/s$