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REVISION QUESTIONS, CHAPTERS 1& 2, CLASS 9 PHYSICS

 CLASS 9 Physics  

Q1 Name any two basic quantities and write their SI units.

 Q2.Name any two derived quantities and write their SI units.

Q3 What are the three requirements for selecting a unit of a physical quantity.? 

Q4. Define “light year". 

Q5. Compare the time periods of two pendulum of length 4m and 25 m.  

Q6. State two factors affecting the time period of a pendulum. State the effects also.  

 Q7. Distinguish between speed and velocity.

 Q8. A car is moving with a velocity of 20 m/s. The brakes are applied to retard it at a rate of 2m/s². What will be the speed after 5 s of applying the brakes? 

 Q9. What does the slope of following graphs represent? 

i) displacement-time  graph  ii) velocity-time graph 

  Q10. Derive the relation: S=ut + ½at² ( any method). 

Q11. A body moves from rest with a uniform acceleration and travels 270 m in 3 s. Find the velocity of the  body at 10 s after the start. 

Q12. Define: i) acceleration ii) acceleration due to gravity.

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