General Science Important Questions Chapter 3 Force and Pressure Class 8 Maharashtra Board

Imp Questions For All Chapters – General Science Class 8

Short Questions

1. What is force?

• Force is a push or pull on an object.

2. What is the SI unit of force?

• The SI unit of force is Newton (N).

3. What are the two types of forces?

• Contact forces and non-contact forces.

4. Give two examples of contact force.

• Muscular force and frictional force.

5. Give two examples of non-contact force.

• Gravitational force and magnetic force.

6. What is friction?

• Friction is the force that opposes motion.

7. What is inertia?

• Inertia is the tendency of an object to resist change in motion.

8. Give an example of inertia of rest.

• A book remains on a table until pushed.

9. Give an example of inertia of motion.

• A moving car stops slowly after brakes are applied.

10. What is pressure?

• Pressure is force applied per unit area.

11. What is the SI unit of pressure?

• The SI unit of pressure is Pascal (Pa).

12. How does pressure change with area?

• Smaller area increases pressure, larger area decreases pressure.

13. Why do sharp knives cut better than blunt ones?

• Sharp knives apply more pressure with less force.

14. What is buoyant force?

• The upward force exerted by a fluid on an object.

15. Why do objects float in water?

• If buoyant force is greater than the object’s weight, it floats.

16. What is atmospheric pressure?

• The pressure exerted by air around the Earth.

17. Why do camels have broad feet?

• Broad feet reduce pressure, preventing sinking in sand.

18. What happens to pressure as we go higher?

• Atmospheric pressure decreases with height.

19. Which scientist discovered buoyant force?

• Archimedes discovered buoyant force.

20. Why do heavy trucks have many wheels?

• More wheels distribute weight and reduce pressure.

Long Questions

1. What is the difference between contact and non-contact forces?

• Contact forces act when objects touch, like friction and muscular force. Non-contact forces act from a distance, like gravitational and magnetic force.

2. What is friction and how is it useful?

• Friction is the force that opposes motion between two surfaces. It helps us walk, hold objects, and stop moving vehicles.

3. How does pressure depend on force and area?

• Pressure increases if force increases or area decreases. That is why knives have sharp edges and elephants have broad feet.

4. What is buoyant force and why do objects float?

• Buoyant force is the upward push of a liquid on an object. Objects float if this force is greater than their weight.

5. What is inertia and how does it affect motion?

• Inertia is an object’s tendency to stay at rest or keep moving. A bus suddenly stopping makes passengers fall forward due to inertia.

6. Why do dams have thick walls at the bottom?

• Water pressure increases with depth, so dams are made thicker at the base to withstand high pressure.

7. What is atmospheric pressure and how does it change?

• Atmospheric pressure is the weight of air around us. It decreases as we go higher above sea level.

8. How does Archimedes’ principle help in shipbuilding?

• Archimedes’ principle states that an object in water experiences an upward force equal to the weight of displaced water. Ships float because they displace enough water to balance their weight.