Force and Pressure 8 Science — Revision Notes
Force is a push or pull that can change an object's motion, shape, or direction, while pressure is the force applied per unit area. Understanding these con
TL;DR: Force is a push or pull that can change an object's motion, shape, or direction, while pressure is the force applied per unit area. Understanding thes…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
Force is a push or pull that can change an object's motion, shape, or direction, while pressure is the force applied per unit area. Understanding these con
Key Points to Remember
- Force is a push or pull acting on an object that can change its state of motion or shape
- Contact forces require direct contact between objects, such as friction, tension, and applied force
- Non-contact forces act at a distance without touching, including gravity and electromagnetic forces
- Newtons are the SI unit of force, named after Isaac Newton
- A balanced force results in zero net force and no change in motion
- An unbalanced force results in non-zero net force, causing acceleration or change in motion
- Pressure is the force applied perpendicular to a surface divided by the area of that surface
- Pascal is the SI unit of pressure, equal to one Newton per square meter
- Pressure increases when force increases or area decreases
- Pressure decreases when force decreases or area increases
- Applications include pressure in hydraulic systems, atmospheric pressure, and pressure in fluids
- Machines like inclined planes, levers, and pulleys reduce the force needed by distributing it over larger areas or distances
Important Formulas
- Force = Mass × Acceleration (F = ma)
- Pressure = Force / Area (P = F/A)
- Atmospheric Pressure = 101,325 Pa or 1 atm
Key Terms
- Force: A push or pull acting on an object that can change its velocity, direction, or shape
- Pressure: Amount of force applied perpendicular to a surface per unit area of that surface
- Contact Force: Force that requires direct physical contact between two objects
- Non-contact Force: Force that acts on objects at a distance without physical contact
- Balanced Force: Equal and opposite forces that result in zero net force and no acceleration
- Unbalanced Force: Unequal forces resulting in a net force that causes acceleration or change in motion
Frequently Asked Questions
What is the difference between force and pressure?
Force is a push or pull with units of Newtons, while pressure is force applied over an area with units of Pascals. The same force can create different pressures depending on the area over which it is distributed
How does reducing area affect pressure?
Reducing the area over which a force acts increases pressure proportionally. For example, a sharp knife applies more pressure than a dull one with the same force because it has a smaller contact area
What is the difference between balanced and unbalanced forces?
Balanced forces are equal and opposite, resulting in zero net force and no change in motion. Unbalanced forces are unequal, resulting in a net force that causes acceleration or change in velocity
More 8 Science Revision Notes
- Crop Production and Management
- Microorganisms: Friend and Foe
- Cell: Structure and Functions
- Reproduction in Animals
- Force and Pressure
- Sound
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