Question

State whether the given statement is true or false.
You find your mass to be 42 kg on a weighing machine. You can say that your mass is more or less than 42 kg
(A) True
(B) False

Answer 1

Hint Weighing machine measures the force exerted on the machine. This force is majorly because of the gravitational mass. However there are other factors like variation of acceleration due to gravity from place to place and buoyancy because of air etc. These factors affect the measurement. Then the actual mass can be more or less than the apparent weight shown due to the net forces acting.

Complete step-by-step answer
Weight is a vector quantity. It is the object's relative mass. When a person is standing on the weighing machine the gravitational force with the acceleration due to gravity is acting downwards which is telling the weight. But this weight is not the true value; it is called an apparent weight because while the weight is acting downwards the upthrust due to the air also acts in the opposite direction that is upwards.
Since, more than one force is acting on the body the net force that is the weight is reduced because of this upthrust. But when we calculate the mass alone the direction is not considered and the force will not be acting hence the true value will be higher than the weight measured on a weighing scale. The value of g is different on different places of earth as well, so the actual weight can be less as well.

Hence, the mass is more or less than 42 kg and the statement is true.

Note Weight is the attractive force exerted by earth on a body while mass is a quantity contained in a body. A body weighing some weight on earth will not have the same weight on the moon or any other planet because the acceleration due to gravity is different which influences the weight whereas mass is independent of.