Question

Tell any two ways to know that motion has occurred

Answer 1

In physics, an object is in motion if it’s moving relative to it’s inertial frame. For me, sitting here in my chair at my desk, I am motionless relative to my living room. I am however sitting on a spinning rock, so relative to the inertial frame where we can see the earth spinning, I am moving. The earth, in the inertial frame of the Earth Moon system is motionless (well, nearly, since the moon’s gravity moves the center of mass in that system a little bit, if discounting the earth’s spin), but in the inertial frame of the solar system, the earth is moving. The sun……

So, pick an object, pick the inertial frame that you care about. The answer within those two relative selections is objective.

Answer 2

1.if there is displacement then motion has occured.

2.if some distance is covered by the object