A model rocket is launched straight upward with an initial speed of 46 m/s. It accelerates with an constant upward acceleration of 2.21 m/s^2 until its engines stop at an altitude of 160.7 m.
What is the maximun height reached by the rocket?
How long after lift-off does it maximum height?
How long is the rocket in the air?
2006-08-24 13:19:20 · 15 answers · asked by Said 4 in Science & Mathematics ➔ Mathematics
m/s is meter per second.
m/s^2 is meter per second squared.
The starting point is ground level.
2006-08-24 13:30:18 · update #1
Bob. I'm not talking about the size of the model rocket.
By "How long is the rocket in the air?", I obviously mean how much TIME it's in the air.
2006-08-24 13:35:47 · update #2
ok, it sounds like it is a (physics) homework problem, but whatever
step 1: first, use the eq, (Vf)^2 = (Vs)^2 + 2*a*(distance) to see what is the final velocity at 160.7m (Vs=46m/s, a=2.21m/s^2, dist = 160.7)
step 2: then, as u find out the final velocity, use the equation (Vf)^2 = (Vs)^2 + 2*a*(distance) again to find out the distance it travel (Vf=0 [for its max height], Vs = ur previous answer, a = -9.8m/s^2), remember to add 160.7 to ur final answer
step 3: then use Vf = Vs + a*t to find out the time it travels (use that equation to find out the time it takes when (i) the engine works
(ii) when the engine fails to work (iii) when it falls down
u should be able to solve this probelm with all these equations.
Ok, if u want the answer, here it is:
(i) max height: 160.7 + 144.2 = 304.9 (if I work my math right, it can be solve by the first 2 steps)
(ii)when engine works: 3.24s
when the engine fails: 5.42s
total time: 3.24+5.42 = 8.66s (using step 3)
(iii)velocity when landed: 77.3m/s (using step 1)
time from high pt to landed: 7.88s (using step 3)
so total time in air: 7.89s + 8.66s =16.55s
Of cuz, it would be right if i do my math right
2006-08-24 13:32:34 · answer #1 · answered by Travis 4 · 0⤊ 0⤋
*What is the maximun height reached by the rocket?
- I think some rockets have a height of about 50metres
*How long after lift-off does it maximum height?
-Its maximum height will not increase even after it takes off
It is still about 50 metres
*How long is the rocket in the air?
-The rocket is still 50 metres even if it is in the air, water or ground!
What a stupid question....
2006-08-24 13:23:21 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The engine stops at 160.7 it is no longer able to keep its upward acceleration and stallsout.
So the engine stalls the rocket flutters and falls.
160.7m mx height.
3.493478 seconds to reach maxium height.
10 seconds in the air. lol a guess. (if im wrong the parachute failed.)
2006-08-24 13:30:02 · answer #3 · answered by Anonymous · 0⤊ 0⤋
42
2006-08-24 13:20:53 · answer #4 · answered by Mr Bean 3 · 0⤊ 0⤋
Are we to assume that the rocket was launched from ground level?
2006-08-24 13:22:29 · answer #5 · answered by naked_in_lake 2 · 0⤊ 0⤋
I agree with Bob
2006-08-24 13:26:33 · answer #6 · answered by pappy 6 · 0⤊ 0⤋
Trick question. Initial speed must be equal to zero.
2006-08-24 13:25:00 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Not without a calculator lol.
It's been nearly 10 years since I was at school, so the brain cells are a little rusty................
2006-08-24 13:25:32 · answer #8 · answered by Anonymous · 0⤊ 0⤋
no im only in 8th grade so far sorry wow bob's smart i agree with him
2006-08-24 13:28:46 · answer #9 · answered by sweetarts13bnh 3 · 0⤊ 0⤋
I forgot how to do integrals. Sorry.
2006-08-24 13:36:05 · answer #10 · answered by Halbert 2 · 0⤊ 0⤋