- #1
Dinovek
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Homework Statement
A rocket is launched off and accelerates vertically up at 10 m/s 2. At 20 seconds, the motors are turned off, but the rocket keeps going up.
a) What height did it reach?
b) What was the time it needed to reach that height?
g: - 9.8 m/s2
a: 10 m/s2
final velocity: 0 m/s (Not sure).
t=20 s
Homework Equations
h= vo (t) + g(t)2/2
t=(vf-vo)/g
vo= vf-g(t)
The Attempt at a Solution
I needed to find initial velocity to find height so I did.
vo=vf-g(t)
vo= 0 m/s - (-9.8m/s2)(20)
vo= 196 m/s
Now I just substituted to find height.
h= vo(t) + (g (t)2)/2
h= 196 m/s (20s) + (-9.8 m/s2 (20) 2)/2
h=3920 m + -3920 m/
h= 3920 m - 1960 m
h= 1960 m
I really have no clue how do to even start the problem because I'm not sure what is the time total. I was thinking that after it stops accelerating, every second it decreases 1 m/s on it's acceleration so that would 10 more seconds to the total timing.
Any help would be appreciated it. Thanks.