Now let us understand what motion is? Motion is a change in an object’s position with respect to time measured in a particular frame of reference. The frame of reference is a view that an individual might use to find out if the object is moving or not.
Let us consider a typical example of travelling on a train. It will seem to you that the trees are moving while you are stationary. It happens as the trees’ position changes concerning our reference frame, including the train. However, our position is not changing concerning the train movement. Hence, it seems that we are stationary.
There are various types of motion, namely,
When a body covers an equal distance in equal time intervals, it is called Uniform motion. In this case, the speed is constant.
When an object covers an unequal distance in equal time intervals, it is called Non-uniform motion. In this case, the speed will vary with time.
Examples of Uniform and Non-uniform motion are trains moving at a constant speed and cars driving on high traffic roads.
Mass is the amount of matter present in an object. It is denoted using “m” or “M.” Its standard unit is kg or gm.
Weight is the quantity of gravitational force that is acting on an object of mass m. It is denoted using “W.”
W=m g , where g is the acceleration due to gravity.
Its standard unit is Newton(N).
Let us talk about the difference between mass and weight.
Mass | Weight |
It is a property of matter. | Weight is proportional to acceleration due to gravity. |
It remains constant irrespective of the location. | Weight of the body changes with a change in acceleration due to gravity. |
It is a scalar quantity and is defined using magnitude alone. | It is a vector quantity and defined using magnitude and direction. |
Mass is never zero. | Weight can be zero(like in space where gravity is zero) |
It is measured using a beam balance. | It is measured using a spring balance. |
Force and Pressure can bring about a movement in the object. Mass and weight are different due to the acceleration due to gravity acting on every object. The weight of a body is zero in space(as g=0).
Force | Pressure |
Force is pushing or pulling a given object. | The pressure is the force applied to a unit area of an object. |
It is measured using Dynometer. | It is measured using Manometer. |
It is defined using magnitude and direction. | It is defined using the magnitude alone. |
Its S.I unit of measurement is Newton(N). | Its S.I unit of measurement is Pascal(P). |