Is there any meaning of Weight of the earth?

A person normally weighing 50kg stands on a massless platform which oscillates up and down harmonically at a frequency of 2.0 s^(-1) and an amplitude 5.0 cm . A weighing machine on the platform gives the persons weight against time. Will there be any change in weight of the body, during the oscillation?

A bird is sitting on the floor of a wire cage and the cage is in the hand of a boy . The bird starts flying in the cage . Will the boy experience any change in the weight of the cage ?

A body weight 72 N moves from the surface of earth at a height half of the radius of the earth , then gravitational force exerted on it will be .......

Assertion: The apparent weight of a person standing in a lift which moves upwards with uniform acceleration is always higher than his true weight. Reason: The weight (on the earth surface) always acts downwards.

Weight fo a body of a mass m decreases by 1% when it is raised to height h above the earth's surface. If the body is taken to depth h in a mine, change in its weight is