Question

The weight of a body on earth is 98 N, where the acceleration due to gravity is 9.8 m s^-2. What will be the mass and weight of the body on the moon? Acceleration due to gravity on the moon is 1.6 m s^-2.

Answer 1

Step 1: Given:

$\text{Weight of the body = 98 N}$.

Step 2: Calculation:

To find the value of the mass of the body and the weight of the body on the moon.

1. Weight of a body is defined as the force with which a body is attracted or pulled towards the centre of the earth.
2. Mass of a body is defined as the total quantity of matter present in the body and is constant throughout the universe including the earth and moon.
3. When a body is at rest on earth's surface, the same force will pull it down onto earth and this is the force we call its weight and is given by:

$\text{Weight of a body = m × g}$.

$\mathbf{\text{mass of the body=}}\frac{\mathbf{weight}\mathbf{}\mathbf{of}\mathbf{}\mathbf{the}\mathbf{}\mathbf{body}}{\mathbf{gravity}}$

= $\frac{98\mathrm{N}}{9.8\mathrm{m}{\mathrm{s}}^{-2}}=10\text{kg.}$

4. Acceleration due to gravity on the moon is $\frac{1}{6}\mathrm{th}$ of the gravity exerted by the earth, so the weight of the body on the moon is given by:

$\text{Weight of a body = m × g}$.

Weight of a body = ${\text{10 kg × 1.6 m s}}^{-2}$.

= 16 N

Hence, the mass of the body is 10 kg and the weight of the body on the moon is 16 N.