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Physics mechanics help?
You are trying to drop essential survival supplies from an aeroplane to help the survivors of a crash who are stranded. You are flying 300m above them, and your aircraft can travel no slower than 30ms^-1. You fly on a straight line which will pass over the survivors.
How far (in metres) in advance of overflying the survivors do you need to drop the package? Assume that the downward acceleration is 9.8 ms^-2.
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3 Answers
- Andrew SmithLv 78 months ago
If you assume that the horizontal velocity is constant ( no air resistance) and that there is no initial vertical component ( dropped ) then h = 1/2 g t^2 -> t = sqrt( 2h/g)
and the horizontal distance moved is vt = v*sqrt( 2h/g) = 30 * sqrt( 2* 300 /9.8) Which is about 235 m. But if the package is moving at 30 m/s when it hits the ground it is going to bounce or roll some unknown distance. So "about 200m" is probably the best answer that could be given.
- nyphdinmdLv 78 months ago
Since the force of gravity only acts in the vertical direction, the supplies move horizontally at the same speed as the plane. Since the plane is not moving vertically, the packages have 0 speed in the vertical direction when first released. So we can copute teh time it take them to fall h = 300m:
y = -1/2 gt^2 "-" = down, "+" = up
Set y = 300 m and g = 9.8 m/s^2 ---> t = sqrt(2y/g) = sqrt(600/9.8) m = 7.825 s
The package move x meters along the ground in th etime t = 7.825 s :
x = v*t where v = 30 m/s ---> x = 234.74 m
So the drop has to be made while the plane is 234.7 m away from the survivors
- Anonymous8 months ago
Sorry, my answer is "Anonymous" as your post is Anonymous. There is no need for an Anonymous question in this category, Most 'Anonymous' posts are trolls, maybe yours is not, but the high likelihood is there. If you post as yourself, I would be glad to help you with any problem you have.
I spend a lot of time on each problem, I just want to make sure it's for a worthwhile cause.