What is weight? Definition and examples

What is weight? Weight, also called force of gravity, is how heavy an object is taking into account the location of the object. 

For example, the weight of an object on the moon is less than the weight of an object on the earth. 

Even here on earth, the weight of an object may vary. You will weigh slightly less at the top of Mount Everest than you would at sea level.

In reality, when you step onto a scale, the scale will return your mass, not your weight. However, people usually refer to the mass as weight.

How to find the weight of an object

One way to find the weight or the force of gravity (F_g) is to multiply the mass of object by the gravity.

If weight = F_g = w, then, Fg = w = mg

m is measured in kg

F_g is measured in Newtons or N

Suppose you step onto the scale and you see 75 kg. What is your weight?

Since you are measuring your weight on the earth, g = 9,807 m/s²

Then, your weight is 75(9.807) = 735.525 N

If you are measuring your weight on the Moon instead,

g = 1,62 m/s²

Then, your weight is 75(1.62) = 121.5 N