Question

State whether weight is a scalar quantity or vector quantity?

Answer 1

Hint: Understand the concept of scalar and vector quantity. Imagine if a physical quantity has both the direction and magnitude or it has only magnitude not direction. This way you can find if the physical quantity is a scalar or vector quantity.

Complete step by step answer:
Scalar quantity can be defined as a physical quantity which has only magnitude, not direction.

A vector quantity can be defined as a physical quantity which has both the magnitude and direction.

Consider the following example.

If we travel from point A to point B. the distance will be 40 km. It has only magnitude. Next if we move backward to point C the total distance travelled is $40+20=60km.$so, distance has only the magnitude, not a direction. So, distance is a scalar quantity.

Now, if we consider displacement it will give the real distance between the points A and C with the direction from A to C. The displacement will be 20 km in the direction A to C. So, displacement is a vector quantity.

Weight can be defined as the force by which a body is attracted towards the centre of the planet. It can be expressed as $w=mg$, where m is mass of the object and g is the acceleration due to gravity. So, we can define weight as a force with direction towards the centre of the planet. weight has both the magnitude and direction. Hence, weight is a vector quantity.

Note: Mass of a body is scalar quantity. Mass has only magnitude, not direction. If we consider weight it is the force experienced by the object due to its mass. Hence, weight has both the magnitude and direction.