A rock is dropped from a tree 240 feet above the ground. How long does it take the rock to hit a branch 24 feet above the ground? Use the vertical motion formula.How to use the Vertical Motion Formula?the ehight above the ground is given vy the equation:
h(t) = 240 - 16t^2
plug in any 't' and it will give you the height.
To solve for a height, set the equation equal to that number and find 't'
your example would be
240 - 16 t^2 = 24
(you will get two answers, it is time, so only use the positive)
How to use the Vertical Motion Formula?If the vertical motion formula from physics is the one you're using then we will use x = vt + .5at^2
Our starting is 240 and ending is 24. Making distance (x) = 216
Since the rock is just being dropped we assume the starting speed is zero so velocity (v) = 0
We are in free fall with no outside force so acceleration (a) = 9.8m/s^2
216 = .5(9.5)t^2
Rearrange the equation and solve for t. It should be about 6.63 seconds.
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