The rate of decrease of kinetic energy is 9.6 J/s. Find the magnitude of force acting on particle when it's speed is 3 ~m / s .

Step-by-step solution

Given, rate of decrease in kinetic energy dk dt =9.6 ~J / s When, speed, v =3 ~m / s then force F = ? Kinetic energy k = 1 2 mv ^2 differentiating with respect to ' t ', we have aligned & dk dt = 1 2 ~m 2 v dv dt = v m dv dt & =v . m dp dt & dk dt = v . F [ force F = mdp dt ] F = 1 v dk dt & = 1 3 9.6=3.2 ~N & aligned