3. Name the physical quantity which remains the same in a uniform circular motion.

4. If both speeds of a body and radius of the circular path are doubled, what will be the change in centripetal force?

5. Is uniform circular motion an example of uniform acceleration? Why?

6. What is the source of centripetal force for a) an electron revolving around a nucleus b) a planet revolving around a star?

7. Why are the passengers of a car rounding a curve thrown outward?

8. Two cards are going in two concentric circular orbits of radius r1 and r2 with angular velocities

w1 and w2. What is the ratio of their linear velocities?

9. Define the term uniform circular motion. For uniform circular motion, prove that V = r w

10. Obtain the relation between time period and angular velocity in a uniform circular motion.

11. A vehicle of mass 500 kg is moving on a curved road of the radius of curvature 50 m. If the coefficient of friction between the tires and the road is 0.1, what is the maximum velocity with which the car can move without skidding?

12. What do you mean by the terms banking and banking angle? Obtain an expression for safe speed on a banked road.

13. In 20 seconds, the speed of motor changes from 1200 rpm to 1800 rpm. In this period of time, the number of revolutions completed by it is?

14. A conveyor belt runs on a wheel of radius 50 cm. As the wheel comes to rest from an initial speed of 4 rps, 50 m, of belt length passes over the wheel. The number of revolutions made by the wheel before stopping is?

15. A body projected horizontally with 98 ms-1 from the top of a tower reaches the ground in 10 s. Then it strikes the ground at an angle?

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