1. A ball is launched horizontally at 40 m/s while 6.0 m above a level field . How far will the ball move horizontally before striking the ground ?

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.

Your answer would be the sun 

An em wave does not require a medium, while a mechanical wave does.