a) Define angular momentum. Write its SI unit. b) The speed of a motor engine decreases from 900 rev/min. to 600rev/min. in 10 seconds. Calculate: 3…

 a) Define angular momentum. Write its SI unit. 

b) The speed of a motor engine decreases from 900 rev/min. to 600rev/min. in 10 seconds.

Calculate: 3

i) The angular acceleration

ii) Number of revolutions made by the motor during this interval

iii) How many additional seconds are required for motor to come to rest in the same rate

             OR

a) For a simple pendulum, show that the acceleration is directly proportional to the displacement of bob from its mean position. 

b) A bob of mass 8kg performs SHM of amplitude 30cm. The restoring force is 60N. Calculate: 

i) Time period ii) The maximum acceleration iii) Kinetic energy when displacement is 12 cm.