Points to Remember: Laws of Motion

Science | Chapter 1

Mechanics is divided into statics and dynamics.
Ability of a body to maintain its state of rest or motion is called Inertia.
Moment of the couple is measured by the product of any one of the forces and the perpendicular distance between two forces.
SI unit of force is newton (N). C.G.S unit is dyne.
When a force F acts on a body for a period of time t, then the product of force and time is known as ‘impulse’.
The unit of weight is newton or kg f
The weight of a body is more at the poles than at the equatorial region.
Mass of a body is defined as the quantity of matter contained in the object. Its SI unit is kilogram (kg).
Apparent weight is the weight of the body acquired due to the action of gravity and other external forces on the body.
Whenever a body or a person falls freely under the action of Earth’s gravitational force alone, it appears to have zero weight. This state is referred to as ‘weightlessness’.