FN max 18000 N 20000 15 000 10000 5000 A 53 ms B 44 ms C 13

F(N) max = 18000 N 20000 15 000 10000 5000 A) 53 m/s B) 44 m/s C) 13500 m/s D) 19 m/s E) 79 m/s t (ms)

Solution

Impulse J = Area of the red cap

               = (1/2) (base)(height)

              = 0.5 (2.5-1)ms (18000 N)

              = 0.5 x 1.5 ms x18000 N

              = 0.5 x1.5 x10 ^-3 s x18000 N

              = 13.5 kg m/s

We know J = m(change in velocity )

From this change in velocity = J/ m

                                         = (13.5 kgm/s)/145 g

                                         = (13.5 kg m/s) /0.145 kg

                                         = 93.1 m/s

Initial velocity u = -40 m/s

Final speed of the ball v = u + change in velocity

                                   = -40 +93.1

                                   = 53.1 m/s

i.e., 53.1 m/s in positive X direction.