How Does Doubling Speed Affect Energy Use Against Drag in Cycling?

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For part (C) you need to consider the power at the new speed and the power at the new speed + head wind. In summary, assuming all energy goes towards working against drag and that F is proportional to v-squared, with a combined mass of 60kg and a speed of 5m/s, the cyclist uses 10kJ of energy to travel 1km with a drag force of 10N. For part (B), if the speed is doubled to 10m/s, the cyclist will use 40kJ of energy to travel 1km. For part (C), when the cyclist slows down to 5m/s and faces a head wind of 5m/s, the power being expended
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justunme
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In this problem assume that all of the energy expended goes into working against drag. Assume that F is proportional to v-squared exactly & that the air is motionless with respect to the ground. Suppose a cyclist and the bicycle have a combined mass of 60kg and is moving a 5m/s.

A) If the drag force on the cyclist is 10N, how much energy does the cyclist use in traveling 1 km?

B) If speed is doubled to 10 m/s, how much energy is used in traveling 1 km?

C) Upon slowing down to 5 m/s, we hit a head wind of 5 m/s, How much power is being expended?

2. Homework Equations

W = Fd

P = W/change in time3. The Attempt at a Solution

A) W = 10N x 1km = 10 kj

B) ?

C) ?
 
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Hi justunme and welcome to PF. For part (B), if the speed is doubled does the drag force change? If so, by what factor?
 

Related to How Does Doubling Speed Affect Energy Use Against Drag in Cycling?

1. What is work in cycling?

Work in cycling refers to the physical effort required to move the pedals and propel the bicycle forward. It is measured in joules and is a product of the force applied to the pedals and the distance traveled.

2. How is power calculated in cycling?

Power in cycling is a measure of the rate at which work is done. It is calculated by dividing the work done (in joules) by the time taken (in seconds). The unit of power is watts, and it is often used to measure a cyclist's performance.

3. How does a cyclist increase their power?

A cyclist can increase their power by improving their strength and endurance through training. This can include weight training, interval training, and longer rides at a steady pace. Proper nutrition and rest are also important factors in increasing power.

4. What role does aerodynamics play in cycling work and power?

Aerodynamics plays a significant role in cycling work and power as it affects a cyclist's overall speed and energy efficiency. Reducing drag from wind resistance can help a cyclist maintain a higher speed with less effort, ultimately increasing their power output.

5. How can a cyclist measure their work and power during a ride?

A cyclist can measure their work and power during a ride using a power meter, which is a device that measures the force applied to the pedals and calculates power output in real-time. This allows cyclists to track their performance and make adjustments to improve their work and power output.

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