Question

3. A car moves with a speed of 30km/h for half an hour,
25km/hour for 1 hour and 40km/h for 2 hours. Calculate the
average speed of the car.
4. Derive the relation S=ut+1/2 at2 graphically.
5. Is uniform circular motion accelerated motion?
6. A rubber band can change its shape on stretching . Will you
classify it as solid or not. Justify (2)
OR
Sponge , though compressible, is a solid? (2)
7. Explain why temperature remains constant during
interconversion of states of matter? (2)
8. Write any three differences between evaporating and
boiling. (2)
9. What is the physical state of water at a) 250⁰c b) 100⁰c. (2)
10. The smell of hot sizzling food reaches you several meters
away, but to get the smell from cold food have to go to
close. Explain. (2)
OR
On suffering from fever which will lower down your body
temperature, more ice or ice cold water? (2)
11. Which type of plastids help in photosynthesis ?
12. Cell wall is made up of which components?
13. If the swollen and raisins is put into salt solution what will
happen?
14. Name the organelle present only in plant which have their
own DNA and ribosomes.
15. Name two structures present in plant cell only not an
animal cell.
16a)In which form does the mitochondria release energy?
Write its full form.
16b) The inner membrane of mitochondria is deeply folded
what is the advantage of these folds?​

Answer 1

Answer:

total time taken=1+2+0.5hours

=3.5hours

total distance traveled=30+25+40km

=95km

average speed=95/3.5km/hr

=27.143km/hr