What causes objects sliding on a surface to stop? You must restate for full credit.

Help please

Which of the following are correct values for the ideal gas laws constant r

Which states of matter have particles that move independently of one another with very little attraction?

Which of the following is a physical change? a.burning a piece of wood b.sawing a piece of wood in half c.rust forming on an iron fence d.a copper roof changing color from orange to green