Force And Pressure Class 8 Questions And Answers
FAQs on NCERT Solutions for Class 8 Science Chapter 8 Force And Pressure 2025-26
1. What is the correct method to solve numerical problems on pressure from the Class 8 Science Chapter 8 NCERT exercises?
To solve any numerical problem on pressure as per the CBSE pattern, you should follow these steps:
- Identify the given values: First, write down the Force (in Newtons) and the Area (in square metres) provided in the question.
- State the formula: Clearly write the formula for pressure, which is Pressure = Force / Area.
- Substitute the values: Place the given values of force and area into the formula.
- Calculate the result: Perform the division to find the value of the pressure.
- Mention the unit: Always end your answer by stating the unit of pressure, which is Pascals (Pa) or Newtons per square metre (N/m²).
2. How should I structure the NCERT solution for the question explaining why a porter places a folded cloth on their head to carry heavy loads?
The correct way to structure this answer for the NCERT solution is to focus on the relationship between pressure and area. Your answer should explain that:
- Pressure is inversely proportional to the area over which a force is applied.
- By placing a folded cloth on their head, the porter increases the surface area of contact between the head and the load.
- This increase in area significantly reduces the pressure exerted on the head, making it much easier and less painful to carry the heavy load.
This step-wise explanation directly links the scientific principle to the practical application, which is key for a complete answer.
3. How does understanding the difference between contact and non-contact forces help in correctly solving the classification questions in the NCERT textbook?
Understanding the core difference is crucial for solving NCERT classification problems. The key is to ask: 'Does the force require physical touching?'
- Contact Forces: To solve for these, identify if there is direct physical contact. Examples in your textbook exercises like muscular force (pushing a book) or frictional force (a ball stopping) require objects to touch.
- Non-Contact Forces: For these, identify if the force acts from a distance. Examples like magnetic force (a magnet attracting iron), electrostatic force (a comb attracting paper), and gravitational force (an apple falling) do not need physical contact.
By applying this simple 'touching vs. not touching' test, you can accurately categorise any force given in the NCERT exercises.
4. When solving NCERT questions about atmospheric pressure, why is it essential to explain that this pressure acts in all directions?
It is essential because it explains why we are not crushed by the immense weight of the air above us. A complete NCERT solution must state that the atmosphere exerts pressure not just downwards, but from all directions—up, down, and sideways. The pressure inside our bodies is balanced by the atmospheric pressure outside. If atmospheric pressure only acted downwards, the unbalanced force would be immense. Mentioning this multi-directional nature shows a complete understanding of the concept beyond a simple definition.
5. What is the proper way to explain why the walls of a dam are built thicker at the bottom, according to the NCERT solutions for Force and Pressure?
A complete solution as per the NCERT guidelines for Class 8 Science should be explained in two clear points:
- First, state the principle: Pressure exerted by a liquid increases with depth. This is the fundamental concept.
- Second, apply the principle: Because the water at the bottom of the dam is much deeper, it exerts significantly more pressure on the walls compared to the water at the top. The thicker base is built to withstand this greater pressure and prevent the dam from breaking.
6. How do you solve the NCERT question that asks to identify the agent, object, and effect of the force in a given situation, like 'squeezing a lemon'?
To solve this type of question systematically, you should break down your answer into three parts for each situation:
- Agent: The entity applying the force. For squeezing a lemon, the agent is our fingers/muscles.
- Object: The entity on which the force is applied. In this case, the object is the lemon.
- Effect: The change caused by the force. Here, the effect is a change in the shape of the lemon and juice being extracted.
Following this structure ensures you address every part of the question clearly.
7. In the NCERT solutions, why is it a common mistake to only mention a 'push' or a 'pull' when defining force, and what is the correct approach?
While a 'push' or 'pull' is a good starting point, it's an incomplete definition for a full-marks answer. A common mistake is not mentioning the effects of the force. For a comprehensive solution as per the 2025-26 CBSE syllabus, you must define force and then describe what it can do. The correct approach is to state that a force is a push or a pull on an object that can:
- Change the object's state of motion (make it move, stop it, or change its direction).
- Change the object's shape.
Including these effects shows a deeper understanding and is crucial for solving application-based questions in the exam.

















