The second runner must run 3.3m/s. If the leading runner is 1.5 seconds ahead and there are 30m left, the second runner would need to run slightly faster than the lead in order to finish at the same time. To calculate this I did 30/1.5 which gave me 0.05. I added this onto the speed of the lead runner to get 3.3m/s :)
The answer is E. Our Universe
Answer:
4400 Joules
73.33 Joules
25.9325 Joules
Explanation:
P = Power = 800 W
t = Time = 22 s
F = Force
r = Radius of arm = 90 cm
Energy

As the efficiency is 25%

Energy used in the race is 4400 Joules
Half of the energy is used in the arm

So, per stroke of paddle

The energy expenditure per arm stroke is 73.33 Joules
Displacement will be the half of the perimeter of the circle

Work done

The average force of the hand on the water is 25.9325 Joules