Question

Suppose,the accelaration due to gravity at the Earth's surface is $10{\text{m/s}}^2$ and at the surface of Mars is $4.0{\text{m/s}}^2$. A $60\text{kg}$ passenger goes from the Earth to Mars in a spaceship moving with a constant velocity. Neglect the influence of all other objects in the sky. Which of the following best represents the weight(net gravitational force)of the passenger as a function of time

• A. $\text{A}$
• B. $\text{B}$
• C. $\text{C}$
• D. $\text{D}$

Answer 1

The correct option is C $\text{C}$

A point would exist in the path of the passenger where the force exerted by earth on passenger would be exactly equal to the force exerted by mars on him. At this position, the net force on the body is zero and hence the weight of body would be zero.
Hence $\text{A}$ and $\text{B}$ not possible.

Weight of the body would always be positive or zero, it cannot be negative, and also it would be zero at one and only one point in between the mars and earth along its path. Before or after that the weight would have a positive value. Hence option (d) is wrong.

Hence, option (c) is the correct answer.

Key Concept: Between two masses, there will be a point where the gravitational field of one mass will be equal and opposite to the gravitational field of the other mass. Why this question: To make students familiar with the concept of gravitational field intensity is a vector quantity.