Of the following situations, which one is impossible?

Question

A body having zero velocity and non-zero acceleration
A body having constant acceleration and variable velocity
A body having velocity east and acceleration east
A body having velocity east and acceleration west
A body having constant velocity and variable acceleration

Answer 1

The only impossible scenario is "A body having constant velocity and variable acceleration"
nonzero acceleration must result in a changing velocity.


All other scenarios are possible:

A body having zero velocity and non-zero acceleration
=a baseball thrown vertically, viewed instantaneously at its apex

A body having constant acceleration and variable velocity
=a rocket leaving earth's orbit

A body having velocity east and acceleration east
=a car accelerating while heading east

A body having velocity east and acceleration west
=a car slamming on the breaks while heading east

Answer 2

A body havin constant velocity and variable acceleration. If you understand calculus, you can show that if dv/dt =0 ( which implies constant velocity), and a = dv/dt (by definition of acceleration) then a = dv/dt = 0, which means acceleration must be 0. If you don't understdand calculus, imagine two points in time t1 and t2, with v1 and v2. If the velocity is constant, then v1 = v2. acceleration is the measure of how much the velocity changes in a set amount of time,
so a = (v2-v1)/(t2-t1)
a = 0/ (t2-t1)
a = 0
So acceleration must be 0 if velocity is constant

Answer 3

A body having zero velocity and non-zero acceleration is not possible.

The reason constant v and variable accelleration is possible is that the body could be travelling on hilly terrain, with less accelleration downhill, and more uphill, but constant velocity.

Answer 4

cONSTANT v AND VARIABLE a.