a ball moves up a hill with an initial velocity of 3m/s. four seconds later, it is moving down the hill at 9.0m/s. find the displacement of the ball from its initial point of release

Answer 1

v(o)=3
v(4)=-9
d(4)=?

average velocity= (vf+vo)/2

displacement= averagevelocity*time
=(-9+3)/2 * 4= -3*4 meters