Coal and Petroleum — Science STD 8 — Question

State two methods of producing sound.

How many reflected rays can there be for a given single incident ray falling on a plane mirror?

Name one destructive natural phenomenon which cannot be predicted in advance.

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 gaps in the following statements using the following terms: muscular, contact, non-contact, gravity, friction, shape, attraction
(a) To stretch the bow, the archer applies a force that causes a change in its ____________ .
(b) The force applied by the archer to stretch the bow is an example of ____________ force.
(c) The type of responsible for a change in the state of motion of the arrow is an example of a ____________ force.
(d) While the arrow moves towards its target, the forces acting on it are due to ____________ and that due to ____________ of air.

What is meant by the ‘flora’ and ‘fauna’ and which belong to ‘flora of the Pachmarhi Biosphere Reserve? Sal, Arjun, Cheetal, Teak, Leopard, Fern, Blue bull, Barking deer, Mango, Wolf.

Why a cell is called the structural and functional unit of living organisms?

If wheat is sown in the kharif season, what would happen? Discuss.

State one change in the body shape of grown up boys and one changes in the body shape of grown up girls which makes them look different.

Why is it easier to slip on a wet surface?

Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room? Explain.