Giving 40 points!

i need to design an experiment to support the hypothesis that light travels in straight lines except at the point it enters a new medium.

a) what can i use for this experiment?
b) how do i use it to complete this experiment? how can i conduct an experiment using it?

The necleus of an atom is made up of what subatomic particles?

A200-n force is applied to the foot-operated air pump. the return spring s exerts a 2.6-n·m moment on member oba for this position. determine the corresponding compression force c in the cylinder bd. if the diameter of the piston in the cylinder is 40 mm, estimate the air pressure generated for these conditions. state any assumptions. enter a positive number for the compression force c.

Diverging mirrors and lenses always produce images