A 40ton rail car and a 80ton rail car, initially at rest, are connected together with a giant but massless compressed spring between them. When released, the 40ton car is pushed away at a speed of 4.8m/s relative to the 80ton car.

What is the speed of the 40ton car relative to the ground?

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.

could you add the photo?

explanation: