When using a pulley with a mechanical advantage of 1.5, a worker applies 250n to the pulley. the pulley is used to lift a heavy crate. how much force does the pulley apply to the crate

Sorry i don't know what mechanical advantage is..also I am not very good at physics..

This is what i found on google “according to the collision theory, the following criteria must be met in order for a chemical reaction to occur: molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. molecules must collide with the proper orientation.” i hope this information you.