Secondary School (English Medium) (5 to 8) Class 8 - CBSE Question Bank Solutions

‘Avoid plastics as far as possible’. Comment on this advice.

An archer stretches her bow while taking aim at the target. She then releases the arrow, which begins to move towards the target. Based on this information fill up the gap in the following statement using the following terms.

The type of force responsible for a change in the state of motion of the arrow is an example of a ______ force.

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

An inflated balloon was pressed against a wall after it has 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?

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.

A rocket has been fired upwards to launch a satellite in its orbit. Name the two forces acting on the rocket immediately after leaving the launching pad.

The system of irrigation where in water is supplied drop by drop near the roots of plants, is called ______.

A bucket made of plastic does not rust like a bucket made of iron. Why?

In human beings, after fertilisation, the structure which gets embedded in the wall of uterus is

In markets, eggs of birds are available but never eggs of dogs. why?

The eggs of frogs do not have shells for protection, yet they are safe in water, how?

State whether the following statement is True or False. If false, correct the statement:

External fertilisation can occur both in water and on land.

State whether the following statement is True or False. If false, correct the statement:

The eggs of fish are covered by hard shells for protection.

State whether the following statement is True or False. If false, correct the statement:

Human egg has a head, middle piece and tail.

Which one of the following forces is a contact force?

Where do we apply a force while walking?

An archer shoots an arrow in the air horizontally. However, after moving some distance, the arrow falls to the ground. Name the initial force that sets the arrow in motion. Explain why the arrow ultimately falls down.

Two rods of the same weight and equal length have different thickness. They are held vertically on the surface of sand as shown in figure. Which one of them will sink more? Why?

How is sound produced and how is it transmitted and heard by us?

State whether the following statement is True or False.

Bathing outdoors should be avoided during thunderstorm.