If the area of contact increases while keeping the thrust constant, the pressure will __________.

Question

Question

This question was previously asked in

RRB JE CBT 2 (Mechanical Engineering) ReExam Official Paper (Held On: 04 Jun, 2025)

Answer 1

The Correct answer is decrease.

Key Points

Pressure is defined as the force per unit area. Mathematically, it is expressed as P = F/A, where P is pressure, F is the thrust or force applied, and A is the area of contact.
If the thrust (F) is kept constant and the area of contact (A) increases, the pressure (P) will decrease as per the inverse relationship.
This principle is based on the fact that spreading the same force over a larger area results in reduced intensity of pressure at any given point.
An example can be seen in snowshoes, which are designed to distribute the weight of a person over a larger area to prevent sinking into the snow.
In practical applications, this concept is used in various fields such as engineering, construction, and material design to ensure proper load distribution and safety.
Thus, when the area of contact increases while maintaining a constant thrust, the pressure will decrease.

Additional Information

Increase
- If the thrust increases while keeping the area of contact constant, the pressure will increase. This is the opposite scenario.
- Applications of this principle include tools and machinery like nails, knives, and hydraulic presses, where smaller contact areas increase pressure to perform cutting or piercing tasks.
Remain the same
- Pressure remains constant only if both the thrust and the area of contact are unchanged.
- This is not applicable in the current scenario since the area of contact is increasing.
First increase, then decrease
- Such behavior is not observed in the relationship between pressure, thrust, and area.
- This option does not align with the formula P = F/A.