Question

If a person of a mass of 80kg starts a race and accelerates to a

speed of 3.2m/s in 5.0s. What is his power?

Answer 1

To find the power generated by a person of 80kg mass who accelerates to 3.2m/s in 5.0s, we calculate the change in kinetic energy as work done and divide by the time interval. The calculated power is approximately 81.92 watts.

Step-by-step explanation:

To calculate the power generated by a person of 80kg mass who accelerates to a speed of 3.2m/s in 5.0s, we use the formula for power in the context of mechanical work:

P = ΔW / Δt

First, we must determine the work done (W), which is the change in kinetic energy (KE) in this case:

ΔW = ΔKE = 0.5 * m * (v2 - u2)

Assuming the person starts from rest (initial velocity u = 0), the change in kinetic energy is:

ΔW = 0.5 * 80kg * (3.2m/s)2

Then, we calculate the power (P) by dividing the work done by the time (t) taken to reach the final velocity:

P = (0.5 * 80kg * (3.2m/s)2) / 5.0s

Now, plugging in the numbers and solving:

P = (0.5 * 80kg * 10.24m2/s2) / 5.0s = (409.6kg*m2/s2) / 5.0s = 81.92W

Therefore, the power generated by the person is approximately 81.92 watts.