at2 In vertical direction, s = 5 m, u = 0 and a = g = 10 m/s. Therefore, 5m =
1
2
10t2 ⇒ t = 1s For the ball, the horizontal displacement is 20 m. Therefore, 20m = vball × t ⇒ vball = 20 m/s or Pball = 0.2 kg × 20 m/s = 4 kg m/s Similarly, Pbullet = 1 kg m/s Therefore, by conservation of momentum, we have that the momentum of bullet before collision as follows: Pball + Pbullet ⇒ 0.01 kg × u = 5 kg m/s or ⇒ u =