Suppose a moving object has 2000 J of kinetic energy. If its mass is 40 kg, what is its speed?

a. 10 m/s
b. 100 m/s
c. 7.07 m/s
d. 44.72 m/s

Question

Suppose a moving object has 2000 J of kinetic energy. If its mass is 40 kg, what is its speed? 

a. 10 m/s
b. 100 m/s
c. 7.07 m/s
d. 44.72 m/s

jamesj · Answer

What is the formula for kinetic energy?

anonymous · Answer

Ya. With the K.E formula, substitute the available values and find the non available value.

anonymous · Answer

use KE=1/2*m/v^2$$1/2 mv ^{2}$$

anonymous · Answer

ans wil be 10 m/s (a)

anonymous · Answer

The Formula for Kinetic Energy is 1/2 m v^2
So set 1/2 m v^2 = 2000 Joules
Solve for v
$$1/2mv^2=2000 J$$$$mv^2=4000 J$$$$v=_{4000/40}^{1/2}$$
10 m/s

anonymous · Answer

Ignore the v equation... I give up on the stupid thing for writing roots.