It is a riddle.

It is the strongest force,

to resist your force,

and yet it is not a force.

It never accelerates,

but it is always moving.

It never rests, and

it never gets tired.

It has been defined many ways,

but no one can quite capture it.

What is it?

The Mathematics formula to express the acceleration:

a = (V-U)/t

At the time of the spinning of the earth, the speed remains contant and it implies that V =U. Let's us replace V to U and we get:

a = (V-V)/t

= 0/t

= 0 acceleration

Or in other words, when the velocity remains constant, there is no acceleration.

As the earth is spinning around the sun at constant speed, that implies that there is no acceleration. But velocity.

Thanks.