# Math Help - Another Physics Question

1. ## Another Physics Question

A green 4 kg toy car with a speed of 5 m/s collides head-on with a stationary yellow 1-kg car. After the collision, the cars are locked together with a speed of 4 m/s. How much kinetic energy is lost in the collision?

a. What is the kinetic energy of the green 4-kg toy car BEFORE the collision?
b. What is the kinetic energy of the yellow 1-kg toy car BEFORE the collision?
c. What is the kinetic energy of the two cars AFTER the collision?

2. ## Re: Another Physics Question

$KE = \frac{1}{2}mv^2$

3. ## Re: Another Physics Question

1/2(4)(5)^2=50J
1/2(1)(0)^2=0J
1/2(5)(4)^2=40J

Lost in collision 50-40=10 J

Is this correct

4. ## Re: Another Physics Question

Originally Posted by Louisana1
1/2(4)(5)^2=50J
1/2(1)(0)^2=0J
1/2(5)(4)^2=40J

Lost in collision 50-40=10 J

Is this correct
Well I'm excited. You even included the units! (Most don't.)