Grade 8 Science - CBSE: Force and Pressure
Chapter Summary: Force and Pressure
KEY CONCEPTS:
- Force is a push or pull that changes the state of motion or shape of an
object.
- Types of forces: Contact force (e.g. muscular force, friction), non-contact
force (e.g. gravitational,magnetic, electrostatic).
- Force has both magnitude and direction.
- Effects of force: It can move a stationary object, stop a moving object,
change the speed or direction, or shape of an object.
PRESSURE:
- Pressure = Force / Area (P = F/A)
- Unit of pressure: Pascal (Pa)
- Liquids and gases exert pressure in all directions.
- Atmospheric pressure is the pressure exerted by air around us.
REAL-LIFE EXAMPLES:
- Broad shoes reduce pressure on soft ground.
- Sucking through a straw works due to air pressure.
- Using syringes and droppers.
QUICK FORMULA:
Grade 8 Science - CBSE: Force and Pressure
Pressure (P) = Force (F) / Area (A)
PRACTICE QUESTIONS:
1. What are the effects of force on an object?
2. Why are sharp knives more effective for cutting?
3. What is the unit of pressure and how is it calculated?
TIPS:
- Always write formula with units in exams.
- Diagrams help you score better: draw forces with arrows.
Chapter Summary: Force and Pressure
KEY CONCEPTS:
- Force is a push or pull that changes the state of motion or shape of an
object.
- Types of forces: Contact force (e.g. muscular force, friction), non-contact
force (e.g. gravitational,magnetic, electrostatic).
- Force has both magnitude and direction.
- Effects of force: It can move a stationary object, stop a moving object,
change the speed or direction, or shape of an object.
PRESSURE:
- Pressure = Force / Area (P = F/A)
- Unit of pressure: Pascal (Pa)
- Liquids and gases exert pressure in all directions.
- Atmospheric pressure is the pressure exerted by air around us.
REAL-LIFE EXAMPLES:
- Broad shoes reduce pressure on soft ground.
- Sucking through a straw works due to air pressure.
- Using syringes and droppers.
QUICK FORMULA:
Grade 8 Science - CBSE: Force and Pressure
Pressure (P) = Force (F) / Area (A)
PRACTICE QUESTIONS:
1. What are the effects of force on an object?
2. Why are sharp knives more effective for cutting?
3. What is the unit of pressure and how is it calculated?
TIPS:
- Always write formula with units in exams.
- Diagrams help you score better: draw forces with arrows.
