Please help me out it would mean a lot!

Four identical lab carts each have a mass of 200 kg. different masses are added to the carts and the velocities are measured. all carts move to the right.

Which best describes the weak nuclear force? it maintains attraction between the m ecules in liquids. it attracts the nucleus of one atom to the nucleus of another atom. it pulls all matter in the universe together it keeps particles that make up protons and neutrons together

The motion of water in a dam serves human beings by generating electricity as it is a controlled motion. give one example for an uncontrolled motion. what effects could it cause