Question

A bicycle rider has a drag area of 0.22 m2. She is riding at a velocity...

A bicycle rider has a drag area of 0.22 m2. She is riding at a velocity of 8.3 m/s along the road and the air density is 1.2 kg/m3. Total mass of the rider and bike is 93 kg. The coefficient of rolling resistance is 0.004. She is riding into a headwind with velocity 1.8 m/s. The road is horizontal. What power (watts) must the cyclist produce to maintain the speed of 8.3 m/s?

Homework Answers

Answer #1

drag force is given by the drag equation=0.5*pho*v^2*Cd*A

where pho=density of air=1.2 kg/m^3

v=speed of the rider w.r.t. air=8.3+1.8 (as headwind means the air is moving in the opposite direction of the vehichle)

==>v=10.1 m/s

drag coefficient for bicylce=0.9

A=0.22 m^2

then drag force=0.5*1.2*10.1^2*0.9*0.22=12.119 N

rolling friction force=coefficient of rolling resistance*normal force

=0.004*mass*g

=0.004*93*9.8=3.6456 N

total force to be applied by the cyclist=3.6456+12.119=15.765 N

then power to be developed=force*speed

=15.765*8.3=130.85 W

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
4. An airplane has a wing area of 428 m2. In flight, the velocity of the...
4. An airplane has a wing area of 428 m2. In flight, the velocity of the air beneath the wing is 250 m/s and the velocity of air above the wing is 290 m/s. The density of air is 1.20 kg/m3. a) Determine the upward force on the WING (HINT: use the Bernoulli Equation) b) Determine the MASS of an airplane that this WING could support in the air c) Is this WING sufficient to support a Boeing 777 with...
12) There are several types of drag on a car other than air resistance. Effects having...
12) There are several types of drag on a car other than air resistance. Effects having to do with the squeezing of the tires (rolling resistance) and frictional forces in the drivetrain (the system that transfers energy from the engine to the rotation of the wheels) also must be taken into account. Engineers use the following equation to model the total force due to these different effects Fdrag=A+Bv+Cv2Fdrag=A+Bv+Cv2 For a Camry, these coefficients are estimated to be A=117.130A=117.130 N, B=1.800...
12) There are several types of drag on a car other than air resistance. Effects having...
12) There are several types of drag on a car other than air resistance. Effects having to do with the squeezing of the tires (rolling resistance) and frictional forces in the drivetrain (the system that transfers energy from the engine to the rotation of the wheels) also must be taken into account. Engineers use the following equation to model the total force due to these different effects Fdrag=A+Bv+Cv2Fdrag=A+Bv+Cv2 For a Camry, these coefficients are estimated to be A=117.130A=117.130 N, B=1.800...
Suzy likes to drive with a silly sun ball on her car antenna. The frontal area...
Suzy likes to drive with a silly sun ball on her car antenna. The frontal area of the ball is 0.0040 m2. As gas prices rise, her husband is concerned that she is wasting fuel because of the additional drag on the ball. He runs a quick test in the wind tunnel at his university and measures the drag coefficient to be 0.30 at nearly all air speeds. Determine the overall car efficiency (with 2 decimal places) if 300 litres...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT