weight W = 735 N
From W = Mg
mass M = W/g = 735/9.81
M = 74.91 Kg
He needs to cover the distance equal to the radius so d= 5 m
He throw m = 1.2 kg mass
speed of book v= 5.0 m/s
we can use momentum conservation to find out the speed of person
Initially total momentum was zero as both were at rest
0 = mv + MV
0 = (1.2x5) + (74.91)V
V = - 0.08 m/s
negative sign just shows the direction of velocity
time taken to cover 5 m distance
d = v*t
t = d/v
t = 5/0.08
t = 62 sec
