Please help! I don't understand. The picture is attached.

Velocity is a description of both speed and direction, therefore it - a vector - a force arrow - the same as acceleration - a magnitude

An initially unpolarized light if intensity 500 w/m^2 passes through four polarizers. the transmission axis between adjacent polarizers is 45∘. what percentage of the initial intensity is transmitted by the system?

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration