Thrust And Pressure

Key notes :

Thrust

Definition:

Thrust is a force that acts perpendicular to a surface. It is exerted by an object when it makes contact with another surface.

Direction:

Thrust always acts at right angles (90 degrees) to the surface of contact.

Examples:

• When a person stands on the ground, their weight exerts a downward thrust on the ground.
• In rockets, the engines produce thrust to propel the rocket upward.

Pressure

Definition:

Pressure is defined as the force applied per unit area. It quantifies how concentrated a force is over a given area.

Formula:

Pressure (P) is calculated using the formula

P = F​/A

Where P is pressure, F is the force applied, and A is the area over which the force is distributed.

Units:

The SI unit of pressure is Pascal (Pa), where 1 Pa = 1 N/m².

Examples:

• A sharp knife has a small area at its edge, leading to high pressure when cutting.
• A person standing on a soft surface (like sand) will sink less than if they were wearing high heels due to the larger area of the heels.

Relationship Between Thrust and Pressure

Direct Relationship:

If the thrust increases and the area remains constant, the pressure will also increase.

Real-World Applications:

Hydraulic systems use the concept of pressure; a small force applied on a small area can create a larger force on a larger area.

Understanding pressure helps in designing structures, such as buildings and bridges, to ensure they can withstand the thrust and pressure exerted on them.

Important Concepts

Fluid Pressure:

In fluids (liquids and gases), pressure acts equally in all directions. The pressure in a fluid increases with depth due to the weight of the fluid above.

Atmospheric Pressure:

The weight of air above us exerts pressure on the Earth’s surface, which decreases with altitude.