Question

-Understand the difference between mass and weight

Without altering their eating habits or exercising, what can a person do to increase or decrease their weight? Mass?

Answer 1

Weight is given by the relation mg.

Case 1:

IF one relocates on top of the mountain, the acceleration due to gravity will be lesser as compared to some place at mean sea level.

If g is lesser atop the mountain, the weight of a person will be correspondingly less.

Case 2:

If one is in an elevator, pseudo forces will act on a person increasing or decreasing the net gravitational force.For an elevator going downwards, the net gravitational force will be m(g-a), where a is the accn of the lift.Hence if we place a scale in the lift, the person will weigh less for the duration in which he is in the lift. Similarly, for a lift going upwards, the net gravitational force acting on the person will be m(g+a) and hence the person will weigh more.

Case 3:

Because of centrifugal force and the oblateness of the Earth, a person will weigh less at the Equator than at the poles.

Mass remains constant always and cannot be altered unless by dietery habits or exercise.