Mass and Weight
• Mass is a quantity which measures the inertia of a body. It is a scalar quantity and is measured in kilogram.
• The weight of an object is the force with which it is attracted towards the earth.
Weight of an object, w = mg
SI unit of weight is newton (N).
• Weight of 1 kg mass is 9.8 N.
• Weight of an object on the moon is the one-sixth weight of an object on the earth surface.
• The condition in which reaction force becomes zero is known as weightlessness.
• When a lift moving up with an acceleration a, then apparent weight = m(g + a).
• When a lift goes down with an acceleration a, then apparent weight = m(g - a).
