Question

A stone of 1kg is thrown with a velocity of 20m/s square across the frozen surface of a lake and it come to rest after travelling a distance of 50m. What is the force of friction beteeen the stone and the ice?....

Answer 1

initial velocity, u=20

final velocity, v=0

displacement, s=50

using v^2=u^2+2as u will get a to be 4m/s^2. hence frictional force acting on body is mass *acc. =1*4=4N