question_answer 59)

  How is the power related to the speed at which a body can be lifted? How many kilograms will a man working at the power of 100 W, be able to lift at constant speed of 1 ms-1 vertically?

Answer:

  (i) The power delivered to a body can also expressed in term of the force F applied to the body and the velocity v of the body where F = Force, S = displacement and t = time                        P = F - v                                                      [v = velocity of the body] Given, power andWe know that, power (P) = F.v                                                                                                             Therefore, man working at the power of 100 W can lift 10 kg.