Is Matter Around Us Pure? — Science STD 9 — Question

Give reason for the following observations. We can get the smell of perfume sitting several metres away.

What is a physical change? Give two examples of physical changes.

Define the terms and given one example: Coelom.

A bus starting from rest moves with a uniform acceleration of 0.1m/ s^-2 for 2 minutes. Find (a) the speed acquired, (b) the distance travelled.

What would happen if the plasma membrane ruptures or breaks down?

What are 'suspended particles'?

Explain why, a small volume of water in a kettle can fill a kitchen with steam.

Akhtar, Kiran and Rahul were riding in a motorcar that was moving with a high velocity on an expressway when an insect hit the windshield and got stuck on the windscreen. Akhtar and Kiran started pondering over the situation. Kiran suggested that the insect suffered a greater change in momentum as compared to the change in momentum of the motorcar (because the change in the velocity of the insect was much more than that of the motorcar). Akhtar said that since the motorcar was moving with a larger velocity, it exerted a larger force on the insect. And as a result the insect died. Rahul while putting an entirely new explanation said that both the motorcar and the insect experienced the same force and a change in their momentum. Comment on these suggestions.