Question

An object weighs 30 N on the surface of Earth . What would be it's weight when measured on the surface of the moon ?

Answer 1

weight = mg 
30 N    = m x 9.8 

30/9.8 = m 

m        = 3.06 kg 

weight on moon = 3.06 x 9.8/6 = 3.06 x 1.63 = 4.998 N 

Answer 2

Given,

An object weighs 30 N on the surface of Earth.

To Find,

It's weight when measured on the surface of the moon =?

Solution,

It is given that an object weighs 30 N on the surface of Earth.

We know,

$Weight = mg_{e}$

Where $m =$ mass of the object

            $g_{e} =$ acceleration due to gravity on Earth

Therefore,

$mg_{e} = 30N$      ------------- (1)

Now, on the Moon, the acceleration due to gravity is 1/6 of the acceleration due to gravity on Earth.

⇒$g_{m} = \frac{1}{6} g_{e}$

The weight of an object on the Moon $= mg_{m}$

                                                               $= m\frac{g_{e} }{6}$     --------------- (2)

Now,

substituting equation (1) in equation (2),

Weight on the Moon $= \frac{30}{6}$

                                   $= 5 N$

Hence, it's weight when measured on the surface of the Moon is 5 N.