(a) Calculate the energy in kJ used by a 55.0-kg woman who does 50 deep knee bends in which her center of mass is lowered and raised 0.400 m. (She does work in both directions.) You may assume her efficiency is 20%. (b) What is the average power consumption rate in watts if she does this in 3.00 min?

Solution 54PE

Step 1

A woman is working and she has to bend her knee half, to do some work. Hence we have to calculate the energy. Given the mass of the women is 55 kg the efficiency of her work is 20% radius is 0.4m and time t is 3min.