Define mass and weight of an object. Write their $SI$ units. An object has a mass of $20 \, kg$ on Earth. What will be its mass and weight on the surface of the Moon? ($g$ on Moon $= 1.6 \, m s^{-2}$)

(N/A) Mass is the quantity of matter contained in an object. The $SI$ unit of mass is $kg$.
Weight is the force with which an object is attracted towards the center of a planet or celestial body. The $SI$ unit of weight is the newton $(N)$.
Since mass is a constant property of an object and does not change with location,the mass of the object on the Moon remains $20 \, kg$.
The weight of the object on the Moon is calculated using the formula $W = m \times g$,where $m = 20 \, kg$ and $g = 1.6 \, m s^{-2}$.
$W = 20 \times 1.6 = 32 \, N$.
Therefore,the mass on the Moon is $20 \, kg$ and the weight on the Moon is $32 \, N$.