Question

In a race, a 54 kg athlete runs from rest to a speed of 11 m/s on a flat surface. The athlete's body has an efficiency 14 of 85 % during the run. How much input energy did the athlete provide?

Answer 1

The input energy provided by a 54 kg athlete accelerating to a speed of 11 m/s with 85% efficiency is 3843.5 J.

Step-by-step explanation:

The question is asking about the amount of input energy provided by a 54 kg athlete who accelerates from rest to a speed of 11 m/s, considering the athlete's body has an efficiency of 85%.

First, we calculate the kinetic energy gained by the athlete, which can be found using the formula E_k = 0.5 * m * v^2, where m is mass and v is velocity. Then, we account for the efficiency of the athlete's body to determine the total energy input required.

Kinetic energy (E_k) = 0.5 * 54 kg * (11 m/s)^2 = 0.5 * 54 * 121 = 3267 J (Joules)

To find the actual energy input by the athlete considering efficiency, we use the formula: Input Energy = E_k / Efficiency. Since efficiency is given in percentage, we convert it to a decimal by dividing by 100. Therefore:

Input Energy = 3267 J / 0.85 = 3843.5 J