A boy Is it running with a kinetic energy of 810 J. If the boy has a mass of 80 kg what is his speed

Question

asked Jan 18, 2020 105k views

2 Answers

Nicolas Repiquet · Answer 1 · 2020-01-20T03:18:56+0000

Answer:

4.5 m/s

Step-by-step explanation:

Kinetic energy is:

KE = ½ mv²

where m is mass and v is velocity.

Given KE = 810 J and m = 80 kg:

810 J = ½ (80 kg) v²

v = 4.5 m/s