What is the initial vertical velocity of the ball? A.
0 m/s

B.
9.81 m/s

C.
20.0 m/s

D.
60.0 m/s

-200 N

Explanation:

Force: This can be defined as the product of mass and acceleration The S.I unit is N

The expression for force is given as

F = m(v-u)/t Equation 1

Where F = Impact force, m = mass of the lorry , v = Final velocity of the lorry , u = initial velocity of the lorry, t = time

Given: m = 6000 kg, v = 0 m/s (the lorry was stopped), u = 0.5 m/s, t = 1.5 s

Substitute into equation 1

F = 6000(0-0.5)/1.5

F = -300/1.5

F = -200 N.

Note: The negative sign shows that the impact force act in opposite direction to the initial motion of the lorry