I had this question about calulating how long it will a vertical leap with a specified height is going to take and what is the initial velocity. Only the final height and gravity (-9.8) is given. But I can't solve it because there are two variables missing -- the time and initial velocity. Is it possible to solve this problem and how.
2006-09-06 11:30:38 · 4 answers · asked by foundation 3 in Science & Mathematics ➔ Physics
ok, I think you can assume that it is a vertical leap downwards, the initial velocity is zero. The acceleration as you plumet downwards is at a rate of 9.8 metres per second, per second. Use this acceleration rate from the height given to calculate the time.
2006-09-06 11:45:18 · answer #1 · answered by Mr D 2 · 0⤊ 0⤋
Hehehe. It's called 'reciprocity' and it means that the time and initial velocity will be *exactly* the same as the time and final velocity for the object falling from the same height.
Another way to work it is to remember that the kinetic energy (mv²/2) at the initial velocity must be exactly equal yo the potential energy (mgh) at the top of the leap since gravity did work against the object as it was going 'up'.
Doug
2006-09-06 11:38:56 · answer #2 · answered by doug_donaghue 7 · 0⤊ 0⤋
one important thing you may not have seen - it's vertical - that cancels out a lot of the required info. question then is how much (starting at zero velocity) acceleration (gravity) is needed to take the object the distance (height), and then double the answer for the return trip. Since it's vertical, doesn't matter what the mass is, and there are no horizontal components to worry about.
2006-09-06 11:37:29 · answer #3 · answered by dimbulb52 3 · 0⤊ 0⤋
Use this equation.
v^2 = 2*g*H, after that you can calculate the other variables.
2006-09-06 11:35:57 · answer #4 · answered by Anonymous · 0⤊ 0⤋