Att=20s velocity of truck, v=0+5×20=100m∕s At 20 sec a ball is dropped from the truck, so velocity of ball will be same as truck. Velocity of truck at x-direction =100m∕s and in y-direction =0. ∴ Velocity of ball vx=100m∕s,vy=0 Now ball will show projectile motion where vertically downward acceleration g=10m∕s act on the ball. As horizontally no acceleration acting on the ball so horizontal velocity 100m∕s will remain unchanged. Velocity of the ball when it reach the ground along y-direction after 1 sec. vy=0−10×1 ⇒vy=−10m∕s ∴ Velocity of ball (