The athlete Emily Davis won the 100 m sprint gold medal at London Olympic 2012 setting a new Olympic record of 10.54 s . Assume that she achieved her maximum speed in a very short time and subsequently ran the race with

Question

Quantrex Academy · Accepted Answer

Correct answer: C. 2250 J

Given that the athlete achieved her maximum speed in a very short time and maintained it throughout the race, her speed can be considered constant.

The constant speed is given by:

v = \dfrac{\text{Distance}}{\text{Time}} = \dfrac{100}{10.54} \approx 9.487 \text{ m/s}

The kinetic energy

K

of the athlete at her full speed is:

K = \dfrac{1}{2}mv^2

Substituting the given values (

m = 50 \text{ kg}

):

K = \dfrac{1}{2} \times 50 \times \left(\dfrac{100}{10.54}\right)^2

K = 25 \times 90.015 \approx 2250 \text{ J}

The athlete Emily Davis won the 100 m sprint gold medal at London...

Options

Correct answer

Step-by-step solution

More from Work and Energy