Mass
• Mass is the amount of matter in a body.
• Mass is a property of a body- that does not. change with its location or shape.
• Mass depends on the number and composition of atoms and molecules that make up a body.
Weight
• The weight of an object is the gravitational force, or gravity acting on it.
• Weight is a vector quantity and the S.I unit is Newton.
• The direction of the weight is downward towards the center of the earth.
Gravitational force
• A gravitational field is a region in which a mass experiences a force due to gravitational attraction.
• The gravitational force experienced is the strongest at the surface of the earth and gets weaker further away.
• Gravitational field strength g is defined as the gravitational force acting per mass.
• The weight of the object depends on the strength of the gravitational force acting on it.
• W = mg
Inertia
• The inertia of an object refers to the reluctance of the object to change its state of rest or motion due to its mass.
• Mass is a measure of inertia. An object with a greater mass will have greater inertia.
• The greater the mass of a body, hardly it will move, slow down, or change direction.
Density
• The Density of a substance is defined as its mass per unit volume.
• Density is how much mass is packed into given spaces.
• P = m / v
• Its S.I unit is kg per cubic meter (kg m³).
• Substances that float on the water have greater densities than water. Substances that sink in water have higher densities than water.
