Answer:
D. 1.4 m/s
Step-by-step explanation:
forward direction is +
back direction is -
Momentum = P = mass x velocity = mv
let v = velocity of ball after collision
Law of Conservation of Momentum: total momentum before the collision must equal the total momentum after the collision
(0.20 kg)(5 m/s) + (1 kg)(0 m/s) = (0.2 kg)(-2 m/s) + (1 kg)v
1 kg·m/s + 0 = -0.4 kg·m/s + (1 kg)v
1 kg·m/s + 0.4 kg·m/s = (1 kg)v rearrange the equation and solve for v
(1 kg)v = 1.4 kg·m/s
v = (1.4 kg·m/s) / (1 kg) = 1.4 m/s