How high up is a 3 kg object that has 300 joules of energy?

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

Why are graphs useful when interpreting data