give examples where velocity of aparticle is zero but acceleration is not zero, velocity is perpendi to accele

Answer 1

For the case of velocity and accleration being colinear (in the same direction) -- if you throw a rock up vertically and it rises, reaches the apex, then comes back down, at the apex the rock would have a velocity of 0 but it is still accelerating towards the ground at a constant rate.

However I don't completely understand what you're asking, since velocity = 0 means you can't really identify a direction associated with the velocity, so it doesn't make much since to say that it is perpendicular to acceleration.

Answer 2

Examples where the velocity is zero, but the acceleration is not zero:

1) Pendulum at either end of its swing.
2) An object thrown up against gravity at its highest point.
3) The tip of the needle of a sewing machine when it is about to change its direction.

Answer 3

Perhaps you want two examples, the second of which being of a particle whose velocity is perpendicular to its acceleration? If this is the case, tie a rock to the end of a piece of string (if you can) and twirl it around. The only force acting on the rock (other than friction) is the force of the string pulling it in the direction of your hand, so the acceleration must be always towards your hand. On the other hand, as the string stays on a circle around your hand, the velocity (derivative of position) must be tangent to the circle, perpendicular to its acceleration. (To test this, let go of the string and observe which direction the rock flies.)

Answer 4

My friend...

Acceleration = (final velocity of a particle - initial velocity of the particle)/time taken for the displacement.

So if the velocity is zero, accelaration is zero too.

However, in a uniform circular motion, the speed is constant, i.e. the magnitude of the velocity is constant, but acceleration is not zero.

Answer 5

Pendulum, When motion reverses, and at the center.

Explanation.

Consider the motion of the pendulum with ball at rest tied to a very long string.

Position C for center, Ball at rest:
At C, V=0, a=0, to moved either way you are applying acceleration that is slightly up and slightly more then gravity,
Position R for Right, Move the ball to the right slightly and let go:
At R, V=0, a=32.2 ft per sec per sec(down), ball starts going down and to the left of this point, V starts increasing(direction to the left).

At C, V=Max, a=0 (momentum now carries) the ball to the left and slightly up to L.

Position L, ball stops going left means V=0, a=32.2 ft per sec per sec(down), ball starts going down and to the right of this point, V starts increasing(direction to the right).

At C, V=Max, a=0 (momentum now carries) the ball to the right and slightly up to R again.

Slowly after many swings ball will rest at C, V=0, a=0(In this position a=32 ft per sec per sec (down), but no motion string does not let it move so a=0.

If the string is very long the ball move in straight line rather then
it an arc for all practical purpose and the motion of the ball, can be considered right to left and left to right, same with other three vectors, distance, velocity and accelerations, only acceleration at play is left to right and right to left, up ward and down ward do not play any roll.

This motion of the ball with infinite length of the string becomes reciprocating motion.

Answer 6

When we throw ball in upward direction , it stops at certain height, where it velocity is zero but its accelaration in downword is 9.8m/sec square that is 'g'.

Answer 7

when an object is projected up it ll have o vel
&accceln is still -10 m/s^2
&when object isin horizontal motion in air like an airplane the 2nd is valid

Answer 8

top of projectile