Given that A=i-2j+3k and B=3i-4k. Find the projection of A on B

Aquarterback pedals 3.3meters southward and then run 5.7meters northward. whats the distance ? and whats the displacement?

Light traveling in water, nwater = 1.33, strikes a plastic block at an angle of incidence of 51.4°; part of the beam is reflected and part is refracted. if the index of refraction of the plastic is 2.0, what is the angle made by the reflected and refracted beams?

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?