2006-08-09 20:42:20 · 14 answers · asked by Connie C 2 in Science & Mathematics ➔ Physics
why not buddy....its very simple just imagine a car decelerating
& then having velocity in reverse direction.....with deceleration now changed to acceleration.And at momenterily rest only velocity is zero not acceleration...
2006-08-09 21:24:02 · answer #1 · answered by v_87_p 2 · 0⤊ 1⤋
Yes
Quote------
If you throw a ball up in the air with velocity V and constant accelaration, a, after reaching maximum height, it will reverse its direction, i.e. it will start comming back down. Just before it changes its direction it will slow down, it means accelaration will become -a instead of a and eventually come to a halt at certain point making a=0 and then again start decending with accelaration a.
---end Quote
Be careful with your directions. + or - indicates direction and the sign of the acceleration (or deceleration) does not change in the above example.
For example:
If you throw a ball up with Velocity of +V, instantaneously it begins to undergo deceleration or -a, or a in the (-) direction if you like. This force -a is constant and it will decelerate (or slow down) the ball to a halt and then begin accelerating (or speeding up) the ball, still in the (-) direction. Now the ball has an increasingly -V.
The ball's acceleration did not change, it was always -a, but the direction of its velocity did.
2006-08-09 21:25:09 · answer #2 · answered by Da Hand 1 · 1⤊ 0⤋
No... an object must come to a momentary stop in order to reverse direction, therefore constant acceleration cannot be maintained. Consider a baseball thrown by a pitcher... at the moment the batter makes contact, the ball comes to a complete stop before it bounces off the bat and goes flying back up the middle, since direction has changed, and velocity is a vector quantity (both speed and direction are included) acceleration must also have changed.
2006-08-09 20:53:09 · answer #3 · answered by eggman 7 · 0⤊ 3⤋
If the acceleration(constant) or its component is opposite to the direction of the velocity of an object then at one stage the velocity will become zero and then its direction will be reversed.
A ball is thrown up with certain velocity. The earth is pulling it down ward with a constant acceleration.
The ball's speed (velocity) is reduced to zero and then its velocity is reversed and comes down.
2006-08-09 20:55:48 · answer #4 · answered by Pearlsawme 7 · 1⤊ 0⤋
No it cant.
V=velocity of an object
a=accelaration
If you throw a ball up in the air with velocity V and constant accelaration, a, after reaching maximum height, it will reverse its direction, i.e. it will start comming back down. Just before it changes its direction it will slow down, it means accelaration will become -a instead of a and eventually come to a halt at certain point making a=0 and then again start decending with accelaration a.
Guyz the question is can it change during constant accelaration. The ball, when it is travelling upwards is de-accelarating i.e. -a. When it halts and comes down the accelaration becomes a. In this case it de-accelarates and then accelarates. They are 2 opposite phenomenons, I dont think it is under constant accelaration.
2006-08-09 21:06:54 · answer #5 · answered by techno_geek 2 · 0⤊ 1⤋
yes it possible, as velocity is a vector & its dependent on both magnitude and direction .
consider a case of a object moving on U curve a object moving on a U curve changes its velocity from +x to -x direction therefore virtully reversing the velocity keeping its magnitude constant
2006-08-09 21:28:02 · answer #6 · answered by Anonymous · 0⤊ 0⤋
Yes of course an object can reverse direction without deccelelerating and instead increasing acceleration but needs lots of space vacant for it not to crash.A planet in motion is constantly changing direction at same velocity.
2006-08-09 20:55:08 · answer #7 · answered by sumant b 4 · 0⤊ 1⤋
reversing the velocity wil definitely change the acceleration, however, if it were speed - it could work.
Velocity being a vector component & speed being scalar.
When u reverse the direction new velocity, v= - (u), where u is the initial velocity.
In your case where u r reversing the direction keeping spped constant, v= -u
thus, a= (v-u )/t = -u-u/t=-2u/t
Hope this helps...
2006-08-09 21:37:34 · answer #8 · answered by debashis j 2 · 0⤊ 0⤋
NOOOOOOOOO . are all you guys nuts acceleration depends on velocity which depends on displacement which is a vector. vctors include direction so you cannot change direction without changing acceleration. about the ball in the air on the way up it undergoes negative acceleration and on the way down it has positive acceleration
2006-08-09 21:14:52 · answer #9 · answered by mad_sci_123 2 · 0⤊ 1⤋
yes.
when u throw a ball upwards then the gravity acts on it downward . at this time the velocity of ball is in the upward direction.when it starts coming down the velocity is in the downward direction. still, the acceleration is acting down wards.
2006-08-10 00:35:16 · answer #10 · answered by Anonymous · 0⤊ 0⤋