A ball of mass 3 kg , moving with a speed of 100 m s - 1 , strikes a wall at an angle 60 ° (as shown in figure). The ball rebounds at the same speed and remains in contact with the wall for 0 . 2 s ; the force exerted by the ball on the wall is:

Step-by-step solution

Change in momentum, ∆ p = m ∆ v ⇒ ∆ p = 3 100 cos 30 ° ⇒ ∆ p = 3 × 2 × 100 × 3 2 ⇒ ∆ p = 300 3 ∆ F = ∆ p ∆ t ⇒ ∆ F = 300 3 0 . 2 = 1500 3   N