Question

Suppose an automobile has a kinetic energy
of 2300 J.
When it moves with nine times the speed,
what will be its kinetic energy?
Answer in units of J.

Answer 1

Answer:

$KE_{new}=186300 J$

Explanation:

Given:

$KE=2300J$   $n=9$

$v_{new}=n*v_{old}$

$\frac{KE_{new}}{KE_{old}}=\frac{v^2_{new}}{v^2_{old}}=\frac{(n*v_{old})^2}{v^2_{old}}=n^2$

$KE_{new}=n^2KE_{old}$

$KE_{new}=(9)^2(2300)$

$KE_{new}=186300 J$

Scientific notation

$KE_{new}= 1.863*10^5 J$

Hope it helps