Answer to Question #138277 in Physics for Malik K Murphy

Question

Jim realizes that he screwed up at the last Engineering
Competition so he decides to build a rocket to impress
Cindy. The rocket is fired into the air and reaches its highest
point 4 seconds later.

A) With what velocity was the rocket fired?

B) How high did the rocket go up?

Answer 1

a)

$$v=gt=(9.8)(4)=39\frac{m}{s}$$

b)

$$h=0.5gt^2=0.5(9.8)(4)^2=78\ m$$