Max is taking his human, Frank, for a walk You can see that Frank is getting dra
ID: 1451881 • Letter: M
Question
Max is taking his human, Frank, for a walk You can see that Frank is getting dragged behind Max, and this means that Max has to pull with a force of 2.90 times 10^2 N. How much power (P_1) does Max have to supply in order to pull Frank at a speed of 0.400 m/s? If Max's body has to generate 145 W of power internally in order to produce the amount of power that you just calculated in Part A, how efficient (element of) is Max's body? How many Joules of energy (E) does Max use in 20.0 seconds when he's generating 145 W of power?Explanation / Answer
(a)
The power exerted by person is, P = Fv = 2.9*10^2 * 0.40 m/s = 116 W
(b)
Efficiency = Pout / Pin= 116 / 145 = 0.8 = 80 %
(c)
Energy U = Power * time = 145 W * 20 s = 2900 J