Answer in Mechanics | Relativity for Chinmoy Kumar Bera #108546

Solution: The second Newton’s law states that the rate of change of momentum of a body is directly proportional to the force applied, and this change in momentum takes place in the direction of the applied force. “vec F=frac{dvec p}{dt}” In our task the directions of force and momentum coincides, and we can write for average magnitudes:

“F=frac{Delta p}{Delta t}” , where increment of the momentum is “Delta p= mcdot Delta v” . Since the ball is initial at rest the speed increment coincides with the final speed “v” of the ball. We have

“Fcdot Delta t=m cdot v” , and “v=frac {Fcdot Delta t}{m}=frac{60Ncdot 10cdot 10^{-3}s}{0.25 kg}=2.4 ms^{-1}”

Answer: speed of the ball just after the impact is 2.4m/s