The strength of friction depends on what two factors

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong chain

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Use the right-hand rule for magnetic force to determine the charge on the moving particle. this is a charge.