Question

An object has a mass of 30 kg. What is its weight (i) on the moon (ii) on another

planet ? The value of ‘g’ on moon is 1/6 the value of ‘g’ on the earth. The value of ‘g’ on

the planet is 3 times the value of ‘g’ on the earth. Take (ge=10 m/s)

Answer 1

Given, mass, m = 30 kg

Acceleration due to gravity on moon, gm = (1/6)g = 10/6 = 5/3 m/s2

Acceleration due to gravity on planet, gp = 3g = 30 m/s2

Now,

Weight on moon = mgm = (30)(5/3) = 50 N

Weight on planet = mgp = (30)(30) = 900 N

.

Answer 2

Given,

Mass of an object = 30 Kg

Acceleration due to gravity is denoted as g.

The value of ‘g’ on the earth = 10 m/s

The value of ‘g’ on the moon = 1/6 × value of ‘g’ on the earth

The value of ‘g’ on a planet = 3 × the value of ‘g’ on the earth

To find,

The weight of the object:

(i) on the moon

(ii) on another planet

Solution,

We can simply solve this numerical problem by using the following process:

Mathematically,

Weight of an object (W)

= Mass of the object (m) x acceleration due to gravity

{Equation 1}

Now, according to the question;

The value of ‘g’ on the moon

= 1/6 × value of ‘g’ on the earth

= 1/6 × 10 m/s

= 10/6 m/s = 5/3 m/s

The value of ‘g’ on the planet

= 3 × the value of ‘g’ on the earth

= 3 × 10 m/s = 30 m/s

Now, according to equation-1;

The weight of the object on the moon

= Mass of the object (m) x acceleration due to gravity on the moon

= 30 Kg × 5/3 m/s

= 50 Kg.m/s = 50 N

The weight of the object on the planet

= Mass of the object (m) x acceleration due to gravity on the planet

= 30 Kg × 30 m/s

= 900 Kg.m/s = 900 N

Hence, the weight of the object is 50 N on the moon and the weight of the object is 900 N on another planet.