How much work is done by a person(105kg) who accelerates from 5.0m/s to 10.0m/s.???

Question

W=?

original text of problem:
How much work is done by an Olympic triathlete who accelerates herself on her bicycle (a combined mass of 105kg) from 5.0 m/s to 10.0 m/s?

Answer 1

Work = change in total mechanic energy of a system

All your work is increasing kinetic energy. Change in KE = work done.

1/2 (105 kg) * ((10 m/s)^2 - (5 m/s)^2) = 1/2 * 105 * 75 (m/s)^2 = 3900 J

Answer 2

W=Force*distance
=F*d
F= Mass*acceleration
=105kg*5
=525newton
D=5m
W=525*5
= 2,625joules
work done is 2625 joules.

Answer 3

The work done all goes into kinetic energy.

Thus, Ke2 - Ke1 = W.

So, 1/2 m * v2^2 - 1/2 m * v1^2 = W
or
W = 0.5 * m * (10^2 - 5^2) = 0.5 * 105 * (100 - 25) = 3938J