Cycle Power Calculation Power [kgm/min] = Force [kg] x Flywheel Distance x RPM *Note: Convert kgm/min to Watts by dividing by 6. 1. Calculate the kgm/min and Watts produced when cycling against 4 kg of resistance with a 6m/revolution flywheel at a pedaling rate of 60 rpm. Kgm/min: ______ Watts: ____
The Correct Answer and Explanation is:
Kgm/min: 1440
Watts: 240
Calculation:
Given:
- Force = 4 kg
- Flywheel distance = 6 meters per revolution
- RPM = 60
- Conversion factor: 1 Watt = 6 kgm/min
Step 1: Calculate Power in kgm/minPower (kgm/min)=Force (kg)×Flywheel Distance (m/rev)×RPM\text{Power (kgm/min)} = \text{Force (kg)} \times \text{Flywheel Distance (m/rev)} \times \text{RPM}Power (kgm/min)=Force (kg)×Flywheel Distance (m/rev)×RPMPower (kgm/min)=4×6×60=1440 kgm/min\text{Power (kgm/min)} = 4 \times 6 \times 60 = 1440 \text{ kgm/min}Power (kgm/min)=4×6×60=1440 kgm/min
Step 2: Convert to WattsWatts=kgm/min6=14406=240 Watts\text{Watts} = \frac{\text{kgm/min}}{6} = \frac{1440}{6} = 240 \text{ Watts}Watts=6kgm/min=61440=240 Watts
Explanation:
This calculation estimates the mechanical power output during cycling using a stationary bike or ergometer. The core of the calculation involves three components. First, the force applied, measured in kilograms, represents the resistance level set on the flywheel. Second, the flywheel distance is the amount of distance the wheel covers per pedal revolution. In this example, the flywheel turns 6 meters for every full pedal stroke. Finally, the revolutions per minute (RPM) reflects how quickly the pedals are being turned.
Multiplying the resistance by the flywheel distance and RPM gives the total mechanical work done per minute, expressed in kilogram-meters per minute (kgm/min). This unit is a common way of expressing physical work in exercise physiology. To convert this value to a standard unit of power like watts, you divide the kgm/min by 6. This factor is derived from the equivalence that 1 watt equals 6 kgm/min.
The result tells us how much power the person is generating. In this case, pedaling with 4 kilograms of resistance at 60 revolutions per minute, with each revolution moving the flywheel 6 meters, results in 1440 kgm/min or 240 watts. This is a solid power output for a steady-state endurance effort and could be used to monitor or compare performance over time.
