Question

Metabolic power is the rate at which your body "burns" fuel to power your activities. For many activities, your body is roughly 25% efficient at converting the chemical energy of food into mechanical energy. What is the cyclist's metabolic power while cycling at 7.3 m/s? Express your answer to two significant figures and include the appropriate units. PMP M =

Answer 1

Answer:

Metabolic power 420.138 W

Explanation:

Given data:

considering drag coefficient Cd =  0.9

Assuming cross section of cyclist A = 0.50 m^2

Take density of air ρ = 1.2 kg/m3

We know that drag force is given as

$Drag\ Force = Cd\times 1/2 \times \rho AV^2$

$D = 0.9\times 1/2\times 1.2\times 0.5\times 7.3^2$

D = 14.388 N

$Power = D\times V = 14.388\times 7.3 = 105.03 W$

hence metabolic power is given as

Metabolic power $= \frac{D}{\eta}$

                   $= \frac{105.03}{0.25}$

                          = 420.138 W