College

In setting one of his world records, sprinter Usain Bolt, who has a mass of 94 kg, reached a speed of 12.41 m/s in 7.41 s. How much power did he exert in watts?

Round your answer to one decimal place and enter only the numerical part of your answer.

Answer :

To determine the power exerted by Usain Bolt, we can follow these steps:

1. Calculate the Change in Kinetic Energy:
- Kinetic energy (KE) is given by the formula: [tex]\( \text{KE} = \frac{1}{2} \times \text{mass} \times \text{velocity}^2 \)[/tex].
- Given mass = 94 kg and final speed = 12.41 m/s, we first calculate the final kinetic energy.
- Initial kinetic energy is zero because Bolt starts from rest (initial speed is 0).
- Change in kinetic energy = Final KE - Initial KE = [tex]\( \frac{1}{2} \times 94 \times 12.41^2 \)[/tex].

2. Calculate Power:
- Power is the rate at which energy is used, calculated by the formula: [tex]\( \text{Power} = \frac{\text{Change in energy}}{\text{Time}} \)[/tex].
- Use the time of 7.41 seconds to find the power exerted.
- Plug in the change in kinetic energy and divide by the time.

3. Round the Answer:
- Finally, round the calculated power to one decimal place.

After performing these calculations, we find that the power exerted by Usain Bolt is 976.8 watts.