A6kg rock is thrown vertically upward from the top of a cliff that is 28m high. it was thrown with a speed of 11ms . calculate the greatest height of the rock as measured from the base of the cliff.

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?

I’ve been stuck on this for a while

The unit of resistivity is the: ohm ohm-cm volt coulomb