Agas is a type of select one: a. matter b. energy c. volume d. mass

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.)

A10 kg box initially at rest is pulled 18 meters across a horizontal, frictionless surface by a 40 n force. what is the block’s final velocity over the 18 meters?

The protons in a nucleus are approximately 2 ✕ 10^−15 m apart. consider the case where the protons are a distance d = 1.93 ✕ 10^−15 m apart. calculate the magnitude of the electric force (in n) between two protons at this distance.