A block of mass M is suspended over a smooth and light pulley via a light string. A constant force F pulls the other end of the string. Over a duration of 1 ext s , the kinetic energy of the block increases by 20 ext J .

Step-by-step solution

Since the string is light and the pulley is smooth and light, the tension is uniform throughout the string. The force F is applied at one end of the string, so the tension T in the string is equal to the applied force F . According to the work-energy theorem, the net work done on the block is equal to the change in its kinetic energy: W_ net = W_T + W_g = K = 20 J Since the block's kinetic energy increases, it has a net acceleration, meaning the net force is non-zero. Therefore, T Mg . The exact values of the work