Question

A boat of mass 40kg is at rest. A dog of mass 4 kg moves in the boat with velocity 10m/s what is the velocity of the boat(nearly) ​

Answer 1

The velocity of the boat is 1m/s

Explanation:

initially boat is at rest and a dog moves over it with 10 m/s at the moment the dog strikes the boat the only force acting is the weight and the reactions which gets cancelled so net force is zero on the system ( boat+dog)

so no external force acting on the system which implies momentum is conserved.

initial momentum = 0

so final momentum = 0

40Xv+4X10 =0

v=1 m/s