Question

Write down the weight of a 50 kg mass on earth.

Answer 1

The weight of a body on a particular planet is the product of its mass and the acceleration due to gravity of the planet. The acceleration due to gravity given should be used, not an assumed one.

Formula used: In this solution we will be using the following formulae; $g = 9.8m/{s^2}$
$W = mg$ where $W$ is the weight of the body on a planet, $m$ is the mass and $g$ is the acceleration due to gravity of the planet.

Complete Step-by-Step solution:
Generally, the weight of a body is dependent on the location of the body. When a body is on earth, the weight of the body is different from the weight when the same body is placed on earth. The weight of a body is the effect of the gravitational form of attraction of the body and the planet (or other celestial body) it is on.
The weight is the product of the mass of the body and the acceleration due to gravity of the planet. This is mathematically given as
$W = mg$ where $W$ is the weight of the body on a planet, $m$ is the mass and $g$ is the acceleration due to gravity of the planet.
Hence, as given from the question, we have
$W = 50 \times 9.8 = 490N$ .

Note:
For clarity, although the question is phrased as though the weight of a body is equal throughout the earth, in reality, it is not. The weight of a body varies with respect to the height from the ground and it also varies with respect to location even on the surface of the earth. The acceleration due to gravity in India is not the same as that in America. Although they are negligible for simple applications.