(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?

Step-by-step solution Step 1 of 7 The formula to find the efficiency is, Here is the efficiency, is the output work and is the input work. Step 2 of 7 (a) The output work done by the woman is, Here is the number of deep knee bends, is the mass of the woman and is the height raised by the center of mass. Step 3 of 7 Substitute for , for , for and for . Step 4 of 7 Since, Therefore,