Can anyone give me an example of a body whose velocity is increasing with time but the acceleration is zero?

Question

Our physics teacher just asked this question in class. And I'm pretty sure it is possible.Acceleration is given by the formula v-u/t.
But if the sum (v-u) is not zero then acceleration cannot be zero!
Please, I need detailed answers.Just the example won't do.

Answer 1

Yes, it is possible.

Let, the body is moving along a circular path
so, here the displacement 's' will be ZERO.

Now let, the initial velocity is 'u' whose value is ZERO
i.e. the body starts moving when it was in rest
also we assume, the acceleration is 'a' & the time is 't'

we know the following equation --

s = u*t + 1/2*a*t^2

now in this equation if we put s=0 ( as in this case displacement is ZERO ) & u=0 ( as here initial velocity is ZERO ) we get --

1/2*a*t^2 = 0
or, a*t^2=0
or,a=0 i.e. acceleration is ZERO

so,in this case whether the velocity is increasing or decreasing the acceleration will always be ZERO.

Answer 2

I assume your teacher is talking about general relativity, where the acceleration and gravity are the same, so simply if you consider that being on the face of the earth is under acceleration equals to 9.81, then you got it.
Imagine a body, maybe a shuttle, flying up with an acceleration equals to 9.81, the sum of the two accelerations will be zero, so the body relatively to the universe will be standing still, however we all agree here on earth that the shuttle is speeding up.

Answer 3

do not difficulty , neither your instructor became incorrect nor you misunderstood it . quite he meant that the linked fee ought to alter with time yet on a similar time acceleration ought to be 0. velocity of a physique is the linked fee of the physique shifting in a particular direction. velocity relies upon on direction besides as velocity. as a result if the direction transformations then velocity will additionally exchange this occurs in relation to a physique which undergoes around action yet strikes with uniform velocity ,right here the direction transformations continuously however the linked fee maintains to be a similar on account that there's no exchange in the linked fee as a result acceleration is 0.eg: planets

Answer 4

By definition this can not be true since acceleration is defined as the change in velocity with time. But if you consider the universe at large and think of the galaxies that surround us, it is possible for one of these to have no acceleration relative to the space it is embedded in but yet whose velocity of recession is increasing with time due to the expansion of the universe. Think of that classic example of the expanding balloon, forget about it's three dimensional structure and consider a bunch of dots scattered about it's surface. None of these dots are moving relative to the surface of the balloon, which is the equivalent of the space we live in, but yet all the dots appear to be moving away from the other dots. And depending on how the balloon, our universe, is exanding, this speed of moving away can be increasing with time.

Answer 5

It is not possible but the reverse is. According to your formula, for acceleration to be zero, v-u needs to be zero that means initial as well as final velocities are same, that means no increase in velocity and so no acceleration.But you say velocity is increasing therefore you can understand now by yourself.

Answer 6

That can never happen. Acceleration is defined as the change in velocity per unit time. So if you have a change in velocity, you're gonna get acceleration. See. Your teacher must be drunk or something.

Answer 7

not possible. A body moving in a circular orbit, even at uniform orbital velocity is undergoing acceleration by a=v^2/r because the velocity vector is constantly changing. for any object that has a change in velocity, there must be an acceleration.

Answer 8

there comes the explanation.


nothing in this world can have increasing velocity with zero acceleration.

as u know acceleration=dv/dt


so if velocity changes , there comes the existance of acceleration.


otherwise not.


well that's what i think is right.

Answer 9

that's impossible....definition of acceleration is the rate at which velocity is changing, the only time acceleration is zero is if velocity is constant.

Answer 10

I don't think there is, because by the definition of acceleration, the velocity must be changing, and vice versa. (if the velocity is changing then there is acceleration)