A 60 kg swimmer suddenly dives from a 150 kg raft with a speed of 1.5 m/s. The raft is initially at rest. What is the speed of the raft immediately after the diver jumps if the water has negligible
effect on the raft?

v2 = 0.6 m/s in opposite direction

Explanation:

The computation of the speed of the raft is as follows

The center of system mass would be remains at the same place also it has no external force applied

Therefore

V = 0

So,  

M1.V1= - (M2.V2)

where,

M1 = 60 kg, V1 = 1.5 m/s

M2 = 150 kg

Now  

60 × 1.5 = - 150 × v2

v2 = -0.6 m/s

v2 = 0.6 m/s in opposite direction

the force required to move the cart is divided by three or 33.33 n.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach