# 1.Rotational inertia is measured in Kg m 2. 2.Set up the formula to convert 45 rev/min into rad/s 45 rev x 2  rad x 1 min min rev 60 s.

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1.Rotational inertia is measured in Kg m 2

2.Set up the formula to convert 45 rev/min into rad/s 45 rev x 2  rad x 1 min min rev 60 s

3. “  ” is the symbol for Angular velocity

4.In the formula W =  , W represents Work

5. “L” is the symbol for Angular momentum

6.A race down an incline between a ring and a hollow sphere of the same mass and radius would be won by the Hollow sphere I ring = mr 2 and I hollow sphere = 2/3 mr 2

8. “  ” is the symbol for Angular acceleration

9. The symbol (variable) for rotational inertia is “I”

10. If the formula for kinetic energy is KE = ½ m v 2, the corresponding formula for rotational kinetic energy is KE = ½ I  2

11. “  ” is the symbol for torque

12. “  ” is the symbol for Angular displacement

13. An ice skater having a rotational inertia of 30 kgm 2 is spinning at 2.5 rad/s. If she increases her inertia to 45 kgm 2, what will be her new angular velocity? I  = I’  ’ (30 kgm 2 ) (2.5 rad/s) = (45 kgm 2 )  ’ 1.67rad/s =  ’

14. How many revolutions are represented by 75 radians? 75 rad x 1 rev = 12 rev 2  rad

15. Set up the formula to convert 120 rad/s to rev/min. 120 rad x 1 rev x 60 s = 1146 rev s 2  rad 1 min min

16. Torque is equal to the applied force times _____ radius

17. Rotational inertia depends on _____ and _____ Mass and radius

18. The label for torque is N m

19. ____ is the motion that results from the sum of two angular velocities Precession

20. What happens to the rotational inertia of an object if its mass moves closer to the axis of rotation? The rotational inertia decreases.

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