A51.0 kg cheetah accelerates from rest to its top speed of 31.7 m/s. hint (a) how much net work (in j) is required for the cheetah to reach its top speed? j (b) one food calorie equals 4186 j. how many calories of net work are required for the cheetah to reach its top speed? note: due to inefficiencies in converting chemical energy to mechanical energy, the amount calculated here is only a fraction of the energy that must be produced by the cheetah's body. cal

(a)

The work-energy theorem states that the work done on the cheetah is equal to its change in kinetic energy:

where

m = 51.0 kg is the mass of the cheetah

u = 0 is the initial speed of the cheetah (zero because it starts from rest)

u = 31.7 m/s is the final speed

Substituting, we find

(b) 6.1 cal

The conversion between calories and Joules is

1 cal = 4186 J

Here the energy the cheetah needs is

Therefore we can set up a simple proportion

to find the equivalent energy in calories:

the force required to move the cart is divided by three or 33.33 n.