Question

Why pressure is a scalar quantity?

Answer 1

Step 1: Scaler and Vector quantities

1. The quantity which only have magnitude is know as scalar quantity.
2. A vector quantity have a magnitude with particular direction.

Step 2: Pressure

1. Pressure is thrust per unit area.
2. While calculating pressure, the force must be perpendicular to the area.
3. As there is only fixed direction that is normal to surface, so pressure is scalar quantity.

Hence, pressure is a scalar quantity because pressure is the ratio of normal force to the area and the direction of force is not required.