- #1

MissJewels

- 34

- 0

## Homework Statement

For 6.5 s, a rocket rises in a straight line oriented at 70° from the horizontal axis with a constant acceleration module of 8m/s

^{2}. Then she is goes into free fall.

Find:

a) the maximum height

b) its horizontal reach

## Homework Equations

t = ( v

_{fv}- v

_{iv})/a

d = v

_{ih}t + (0.5)at

^{2}

I believe?

y= y

_{i}+ v

_{yo}t -(0.5)gt

^{2}

x= v

_{xo}t

## The Attempt at a Solution

so ive got these given infos:

t= 6,5

x

_{i}= 0

x

_{f}= ?

y

_{i}= 0

y

_{f}= ?

a= 8 m/s

^{2}

a) to find y

_{f}at v

_{f}=0

y= v

_{o}(sin(70))t -(0,5)(9,8)t

^{2}

But then, i wonder if i should replace gravity with acceleration, but seeing as were working with y, doesnt that mean i HAVE to use -9,8 as my g (or a) value? From what i understand, I only use 8m/s

^{2}when i have to calculate wth the values of x? I'm confused. Someone explain that at least! I have a strong feeling im heading in the wrong direction with my work so far. Boost me?

b) as for this one, im guessing i have to find x

_{f}after 6,8 seconds once i find the value of v

_{0}, I'm guessing things will fall into place. But do correct me if im wrong?