130k views
0 votes
An 80 kg runner has 3,000 J of kinetic energy. What is her velocity in m/s?

1 Answer

7 votes

Answer: 8.6m/s

Explanation:From KE=1/2mv^2

In order to make v the subject of the formula we divide both sides by 1/2m. Thus V^2 will be left alone on the RHS. But we are looking for v and not v^2. Thus we find the square root of KE1/2m

Meaning V= sqrt[3000÷1/2 of 80]

=sqrt[3000÷40]

=sqrt(75)

=8.6m/s

User Rommudoh
by
4.6k points