Force and Pressure — Class 8 Science NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 8 Science chapter "Force and Pressure" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 8 Science chapter "Force and Pressure" — 8 important questions with detailed answers for CBSE board exam p…

By Syllab.in · Updated Jun 14, 2026

Key Questions Covered:

Define force. State its SI unit.
A force of 100 N acts on an area of 5 m². Calculate the pressure.
Why does a sharp knife cut better than a blunt one?
Calculate the force exerted by a pressure of 50 Pa on an area of 2 m².
What are contact forces? Give two examples.
State the difference between balanced and unbalanced forces.
+ 2 more questions in the full chapter

Solutions Summary:

Question	Status
Define force. State its SI unit.	✓ Solved
A force of 100 N acts on an area of 5 m². Calculate the p…	✓ Solved
Why does a sharp knife cut better than a blunt one?	✓ Solved
Calculate the force exerted by a pressure of 50 Pa on an …	✓ Solved
What are contact forces? Give two examples.	✓ Solved
State the difference between balanced and unbalanced forces.	✓ Solved

Showing 6 of 8 questions

Q1: Define force. State its SI unit.

Force is a push or pull that changes or tends to change the state of rest or motion of an object. SI unit: Newton (N). 1 N = 1 kg·m/s².

Q2: A force of 100 N acts on an area of 5 m². Calculate the pressure.

Step 1: Use formula P = F/A Step 2: P = 100/5 = 20 Pa Pressure = 20 Pascal

Q3: Why does a sharp knife cut better than a blunt one?

A sharp knife has a smaller contact area. Since pressure P = F/A, smaller area produces greater pressure for the same force. Higher pressure cuts through objects more easily than a blunt knife.

Q4: Calculate the force exerted by a pressure of 50 Pa on an area of 2 m².

Step 1: Use P = F/A → F = P × A Step 2: F = 50 × 2 = 100 N Force = 100 Newton

Q5: What are contact forces? Give two examples.

Contact forces are forces that act when two objects are in direct contact. Examples: (1) Normal force when an object rests on a surface, (2) Friction between two sliding surfaces, (3) Tension in a rope, (4) Applied force when pushing an object.

Q6: State the difference between balanced and unbalanced forces.

Balanced forces: Equal in magnitude, opposite in direction; produce no net change in motion. Unbalanced forces: Unequal magnitudes or directions; cause acceleration or change in motion. Balanced forces keep objects at rest or moving with constant velocity.

Showing 6 of 8 questions. Visit the full page for complete solutions.