Ablock is pulled across a flat surface at a constant speed using a force of 50 newtons at an angle of 60 degrees above the horizontal. the magnitude of the friction force acting on the block is:

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.

A., d., and f i think

Amethod of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.