Question

a flat car of mass M is at rest on a frictionlesss floor with a child of mass m standing at its edge is child jumps of from the car towards right with an initial velocity u with respect to car find the velocity of car after its jump​

Answer 1

Explanation:

a flat car of mass M is at rest on a frictionlesss floor with a child of mass m standing at its edge is child jumps of from the car towards right with an initial velocity u with respect to car find the velocity of car after its jump

Answer 2

Let car attains a velocity of magnitude v leftwards, and the net velocity of the child with respect to earth will be u−v, as u is its velocity with respect to the car. Initially. the system was at rest, thus according to momentum conservation momentum after jump must be zero, as

m(u−v)=Mv
v= m+M/mu
​
Hence, the velocity of the car after its jump is v= m+M/mu