Problem 11.64 Part A When you ride a bicycle at constant speed, nearly all the d
ID: 1394676 • Letter: P
Question
Problem 11.64 Part A When you ride a bicycle at constant speed, nearly all the do against the drag force of the air. Model a cyclist as having cross-section area 0.45m2 and, because the human body is not aerodynamically shaped, a drag coefficient of 0.90 What is the cyclist's power output while riding at a steady 7.3 m/s (16 mph)? energy you expend goes into the work you Express your answer to two significant figures and include the appropriate units. P= 95W Submit My Answers Give Up Correct Part B 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 power while cycling at 7.3 m/s? Express your answer to two significant figures and include the appropriate units. . What is the cyclist's metabolic R380 W Submit My Answers Give UpExplanation / Answer
Here ,
Area , A = 0.45 m^2
C = 0.90
Drag force , F = 0.5 * p * v^2 * C * A
F = 0.5 * 1.2 * 7.3^2 * 0.90 * 0.45
F = 12.95 N
Power = F*v
Power = 12.95 * 7.3
Power = 95 W
B)
energy burned = Power output /efficiency
energy burned = 95/.25
energy burned = 380 W
C)
caloried burned in 1 hour = Power * time /4190
caloried burned in 1 hour = 380 * 3600/4190
caloried burned in 1 hour = 326.5 Cal