Ray G. answered • 03/20/15

Intro physics to calculus based physics. It's all good.

a) First of all, when something is thrown up and returns to the ground the total displacement of the object is 0 (zero)

So s(t) = 0 ft

0 = -16*12

^{2}+ v_{0}*120 = -2304 + v

_{0}*122304 = Vo*12

2304/12 = Vo

**192 ft/sec = Vo**

b) Next when something is thrown up and returns to the ground the time it takes going up = the time it takes falling down. Since the total time was 12 sec, the time going up is 6 sec. That is the time to reach its highest point.

s(t) = -16*6

^{2}+ 192*6**s(t) = 576 ft**

Hope this helps!