Final answer:
The answer is option 4.The time it took for the runner to achieve a speed of 5 m/s with a power output of 250 W and a mass of 60 kg is calculated to be 3.0 seconds.
Step-by-step explanation:
To find the time it took for the runner to reach a speed of 5 m/s, we can use the formula:
Power = Force x Velocity
Given that the power generated by the runner is 250 W, and the mass of the runner is 60 kg, we can calculate the force using the formula:
Power = Force x Velocity
250 W = Force x 5 m/s
Solving for force:
Force = 250 W / 5 m/s = 50 N
Now, we can use Newton's second law of motion to find the acceleration of the runner:
Force = mass x acceleration
50 N = 60 kg x acceleration
Solving for acceleration:
acceleration = 50 N / 60 kg = 0.8333 m/s^2
Finally, we can use the formula for acceleration to find the time it took for the runner to reach a speed of 5 m/s:
acceleration = (final velocity - initial velocity) / time
Plugging in the values:
0.8333 m/s^2 = (5 m/s - 0 m/s) / time
Solving for time:
time = (5 m/s - 0 m/s) / 0.8333 m/s^2 = 6 seconds
Therefore, it took the runner 6 seconds to reach a speed of 5 m/s.