NCERT Solutions For Class 8 Science Chapter 8 Force And Pressure VSAQs

NCERT Solutions For Class 8 Science Chapter 8 Force And Pressure VSAQs

Question 1. Can you lift or push a book lying on a table without touching it?
Answer:

No, we cannot lift or push a book lying on a table without touching it because it is a type of contact force.

Question 2. What happens when you apply a force to an inflated balloon by pressing it between your palms?
Answer:

The shape of a balloon will change if we apply a force to an inflated balloon by pressing it between our palms.

Question 3. What does the force come from when we push an object like a school bag or lift a bucket of water?
Answer: This force is caused by the action of muscles in our body.

Question 4. List a few examples of the force exerted by the muscles in our body.
Answer: Chewing of food, lifting of luggage, and squeezing a sponge ball.

NCERT Class 8 Science Chapter 8 Force and Pressure VSAQs

Question 5. Leaves and fruits fall to the ground when they get detached from the plant. Have you ever wondered why it is so?
Answer:

Leaves and fruits fall towards the ground because Earth pulls them towards it, and this attractive force is known as the force of gravity or gravitational force.

Question 6. Is there any relation between pressure and force?
Answer:

Yes, pressure is force per unit area. Thus, we can say that pressure is directly proportional to force.

Question 7. Paheli wants to understand why porters place a round piece of cloth on their heads when they carry heavy loads.
Answer:

When a porter places a round piece of cloth on his head, it reduces the pressure on the head as the area ofcontact increases, and they find it easier to carry the load.

Question 8. Can you explain why shoulder bags are provided with broad straps and not thin straps?
Answer:

School bags are provided with broad straps because they increase the surface area of contact with the shoulder, which results in reducing the pressure on the shoulder.

NCERT Solutions for Force and Pressure Chapter 8

Question 9. Boojho has seen fountains of water coming out of the leaking joints or holes in pipes supplying water. Is it due to the pressure exerted by water on the walls of the pipes?
Answer:

Yes, water coming out of the leaking joints or holes in pipes supplying water is due to the pressure exerted by water on the surface of the pipes.

Question 10. Why is it easier to cut the fruit with a sharp knife as compared to a blunt knife?
Answer:

The surface area of a sharp knife is less than that of a blunt knife, so the pressure applied by a sharp knife is higher than blunt knife.

Question 11. In the following situation, identify the agent exerting the force and the object on which it acts. State the effect of the force in each case.

1. Squeezing a piece of lemon between the fingers to extract its juice.
2. Taking out paste from a toothpaste tube.
3. A load is suspended from a spring while its other end is on a hook fixed to a wall.
4. An athlete is making a high jump to clear the bar at a certain height.

Answer:

Force and Pressure VSAQs Class 8 NCERT Solutions

Question 12. A blacksmith hammers a hot piece of iron while making a tool. How does the force due to hammering affect the piece of iron?
Answer:

When a blacksmith hammers a hot piece of iron, the force due to hammering can change the shape of the piece of iron. In other words, we can say that the force applied through the hammer by the blacksmith can mould the hot piece of iron into any kind of tool.

Question 13. An inflated balloon was pressed against a wall after it had been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. What force might be responsible for the attraction between the balloon and the wall?
Answer:

As the balloon has been rubbed with a piece of synthetic cloth, it has acquired some electrostatic charge and become a charged body. Now, when this charged body (which is a balloon) is pressed against the wall, it will get attracted. Thus, the electrostatic force is responsible for the attraction between the balloon and the wall.

Question 14. Name the forces acting on a plastic bucket containing water held above ground level in your hand. Discuss why the forces acting on the bucket do not bring a change in its state of motion.
Answer:

The forces acting on a plastic bucket are the gravitational force and the muscular force. These forces do not bring a change in its state of motion because, being equal and opposite in magnitude, the effect of the net force on the bucket becomes zero.

NCERT Solutions for VSAQs on Force and Pressure

Question 15. A rocket has been fired upwards to launch a satellite into orbit. Name the two forces acting on the rocket immediately after leaving the launching pad.
Answer: Two forces are as follows:

1. Gravitational force
2. Friction due to air or the force of friction

Question 16. When we press the bulb of a dropper with its nozzle kept in water, air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water fills the dropper. The rise of water in the dropper is due to

1. Pressure of water
2. Gravity of the Earth
3. Shape of rubber bulb
4. Atmospheric pressure

Answer: 4. Atmospheric pressure.