2006-08-19 06:06:09 · 19 answers · asked by a7aa 1 in Science & Mathematics ➔ Physics
I will prove that it must be zero.
If it still had an upwards velocity when it reached its highest point, it would carry on a bit further and so it wouldn't have been its highest point would it?
If it had a downwards velocity when it reached its highest point, it must, a moment before have come from a higher-up point and so the point it next reaches wouldn't be its highest point would it?
Therefore as there are only three alternatives (upwards velocity, downwards velocity and zero) and two of these lead to a contradiction then it must be the third alternative, zero, that is the right answer.
2006-08-19 06:38:41 · answer #1 · answered by Anonymous · 5⤊ 0⤋
The instant the object reaches its highest point; the object has zero velocity as it is continually decelerating....its velocity decreases to zero and then continues to decrease into the negatives. At some point after its launch (the highest point in its trajectory) the object will have an upward velocity of zero.
2006-08-19 06:11:53 · answer #2 · answered by mrjeffy321 7 · 0⤊ 0⤋
the velocity of the ball at the highest point is zero
2006-08-19 06:13:47 · answer #3 · answered by Anjali 1 · 0⤊ 0⤋
0
The ball, when thrown has a velocity going up. Acceleration due to gravity goes down. So the ball slows down, At the top of its path, the acceleration has reduced the speed to 0. The it will oon fall down. As it does, its velocity is now going down, in the same direction as gravity. So the ball picks up speed.
2006-08-19 06:16:18 · answer #4 · answered by dennis_d_wurm 4 · 0⤊ 0⤋
When it reaches it's highest point, it stops and begins to fall, so at it's highest point, the velocity is zero.
2006-08-19 06:13:21 · answer #5 · answered by Walking Man 6 · 0⤊ 0⤋
Zero
2006-08-19 06:12:16 · answer #6 · answered by IdahoMike 5 · 0⤊ 0⤋
ZERO at the highest pt the ball stops & changes its direction downwards
2006-08-19 06:48:57 · answer #7 · answered by Anonymous · 0⤊ 0⤋
the answer is 0
this is because at the highest point its kinetic energy is 0 and its potential energy is max
i.e 1/2*mass*velocity^2= 0 ; therefore velocity = 0
potentila energy = mass* gravity* height above ground
2006-08-19 08:12:39 · answer #8 · answered by clayonjj 1 · 0⤊ 0⤋
Its velocity is zero but it is still accelerating downwards at 9.8 m/s2. It has stopped but its velocity is still changing (it was moving the instant before and it will be moving the instant after.)
2006-08-23 01:54:14 · answer #9 · answered by kemchan2 4 · 0⤊ 0⤋
Zero only when measured from the ground. If you measure it from space, then the speed will be the earth's rotation. Likewise, it will be a different velocity if you choose a moving reference frame.
2006-08-19 11:21:47 · answer #10 · answered by Anonymous · 0⤊ 0⤋