Need help with this question about speed. PLEASE?

Question

In Denver, children bring their old jack-o-lanterns to the top of a tower and compete for accuracy in hitting a target on the ground. Suppose that the tower height is h = 10.80 m, and that the bulls-eye's horizontal distance is d = 3.9 m from the launch point. If the pumpkin is thrown horizontally, what is the launch speed needed to hit the bulls-eye? (Neglect air resistance.)



Thank you very much i have been stuck on this problem for awhile now. God Bless.

Answer 1

You can consider the horizontal and vertical motion separately. First figure out how long it will take to drop 10.80 m (vertically). Then divide this time into 3.9 m which will give you the required horizontal velocity of the pumpkin.

To determine the time it takes to fall a given distance, the equation is t = √(2x/g).

x = 10.8 m
g = 9.8 m/s²

√(21.6/9.8) ≈ 1.5 seconds

3.9 m / 1.5 s ≈ 2.6 m/s

So if you throw the pumpkin horizontally at 2.6 m/s it should hit the ground 1.5 seconds later hitting the bulls-eye 3.9 meters away.

Answer 2

since the pumpkin are thrown off horizizonally, it's no difference that dropping it. Does not matter how fast the pumpkin are thrown off horizonally, the time it takes the pumpkins to hit the ground is the same time it takes the pumpkin that is dropped.

So find the time it takes the pumpkin to hit the ground
t = sqrt(2d/g)
t = sqrt(2*10.80/9.8)
t =~ 1.484s

distance = speed * time
3.9 = 1.484v
v = 2.63 m/s

Answer 3

a humorous question. yet no longer quite sensible. Darkness does no longer go back and forth. Darkness is not any element so it does no longer quite have a speed. you would possibly want to ascertain it because the speed at which gentle is going away. which may be the exact same because the speed of light. i'd say the speed of darkish is 'a effective element to philosophize about'