Question

How much would a 70 kg man weigh on the moon? What would be his mass on the Earth and on the moon? (Acceleration due to gravity of moon $= 1.63\,m/{s^2}$)

Answer 1

The weight of a person is the product of their mass and the gravitational acceleration experienced by them. Their mass is independent of the gravitational acceleration but their weight does depend on it.
Formula used: In this solution, we will use the following formula:
Weight of a person: $W = mg$ where $m$ is the mass of the person and $g$ is the gravitational acceleration they experience.

Complete step by step answer:
We’ve been given the mass of a man as 70 kg. We want to find his weight on the moon. We know that the weight of the man is calculated as
$W = mg$
Since the gravitational acceleration on the moon has been given to us $= 1.63\,m/{s^2}$, the weight of the man on the moon will be
$W = 70 \times 1.63$
$\Rightarrow W = 114.1N$
Hence the weight of the man on the moon will be $114.1$ Newtons which is the actual unit of weight of the man.
Now the mass of the man will be constant irrespective of whether he is on the Earth or on the moon since mass is an intrinsic property of matter. Hence the mass of man on Earth and the moon will be 70 kg.

Note: In daily life, we often use kilograms to indicate the weight of an object. However, it is the weight of the object in Newtons that we are measuring. So, we must not get confused between the mass of the person and the weight of the person. In this question, we’ve been given the mass of the person and not their weight.