Top Questions and Answers on Force and Pressure – Class 8 Science Guide

Understanding force and pressure is crucial for students studying Class 8 Science. This guide offers over 50
concise, exam-ready Q&A-style explanations from the NCERT syllabus. Whether you want to understand the types
of forces, effects of pressure, or how they apply in real life, these insights will boost your conceptual clarity
and help you ace your exams.

What is Force in Science?

Q: What is force?
A: Force is defined as a push or a pull that can change the state of motion or shape of an object.

Q: How does force arise?
A: Force arises due to the interaction between two objects.

Q: What are the two main types of force?
A: Force can be a push or a pull.

Types of Forces and Their Effects

Q: What are contact forces?
A: Forces that require physical contact, such as muscular force and friction, are contact forces.

Q: What are non-contact forces?
A: Forces that act without contact, such as magnetic force, gravitational force, and electrostatic force.

Q: What can a force do to an object?
A: Force can move a stationary object, stop a moving object, change its direction, change its speed, or change its shape.

Friction and Muscular Force

Q: What is friction?
A: Friction is a force that opposes motion and acts between two surfaces in contact.

Q: Why does a ball stop rolling on the ground?
A: Because friction between the ball and ground slows it down.

Q: What is muscular force?
A: The force applied by our muscles, such as lifting or pulling objects.

Gravitational and Magnetic Forces

Q: What is gravitational force?
A: The force with which Earth attracts objects towards its center.

Q: Give an example of gravitational force.
A: A falling apple or a coin dropping to the ground.

Q: What is magnetic force?
A: The force between magnets, where like poles repel and opposite poles attract.

Electrostatic and Atmospheric Pressure

Q: What is electrostatic force?
A: The force exerted by a charged object on another object without contact.

Q: What is atmospheric pressure?
A: The pressure exerted by the air in Earth’s atmosphere on everything.

Q: Why doesn’t atmospheric pressure crush us?
A: Because the pressure inside our body balances the external pressure.

Understanding Pressure

Q: What is pressure?
A: Pressure is the force applied per unit area.

Q: Write the formula for pressure.
A: Pressure = Force / Area

Q: Why is it easier to cut with a sharp knife?
A: A sharp knife applies force over a smaller area, increasing pressure and making cutting easier.

Q: Why do porters use a cloth pad while carrying loads?
A: To increase the contact area, reducing pressure on their heads.

Pressure in Liquids and Gases

Q: Do liquids exert pressure?
A: Yes, liquids exert pressure on the walls and bottom of the container.

Q: Do gases exert pressure?
A: Yes, gases exert pressure on the walls of their container, as in an inflated balloon.

Q: Why do water pipes sometimes leak at joints?
A: Because of the water pressure inside pushing against the joints.

Conclusion: Why You Should Master Force and Pressure

Force and pressure are key concepts in physics that apply to countless real-life situations. From the way
we walk to the functioning of machines and nature’s phenomena, understanding these principles builds
strong scientific literacy. Bookmark this guide and revisit it for quick revision before your exams!