Is it reasonable that a 30-kg child could run fast enough to have 100 J of kinetic energy? (A). Yes, this is reasonable (B). No, this is not reasonable

Question

asked Aug 26, 2023 205k views

1 Answer

Brian Putnam · Answer 1 · 2023-09-01T19:22:11+0000

Answer:

A.) Yes, this is reasonable

Step-by-step explanation:

The formula for kinetic energy states
E_k=(1)/(2)mv^2 :

$E_k=100J\\m=30kg$

Rewrite the formula to solve for v:

$v=\sqrt((2E_k)/(m))\\v=\sqrt(((2)(100J))/(30kg))\\v=\sqrt(6.67(m^2)/(s^2))\\v=2.58(m)/(s)$

2.58(m)/(s) translates to approximately 5.77 mph. Which seems reasonable enough for a child.