Two pulleys have radii of 15 cm and 8 cm, respectively. The larger pulley rotates 25 times in 36 sec. Find the angular speed of each pulley in radians per second.

Question

ganeshie8 · Answer

Angular speed, is simply the rate of change of angle  :-

change in angle
--------------
         time

ganeshie8 · Answer

lets work the larger pulley first,

its making 25 full rotations in 36 seconds
1 full rotation = 2 pi angle

ganeshie8 · Answer

so, how much angle is turned in 36 seconds ?

artemisxrpg · Answer

25pi/18?

ganeshie8 · Answer

In 36 seconds, 25 x 2pi = 50 pi angle is turned

so Anglular speed of larger pulley = 

50pi
------   =  25pi/18
36

ganeshie8 · Answer

you're correct !

ganeshie8 · Answer

how do we find the angular speed of smaller pulley ? any ideas ? :)

artemisxrpg · Answer

i'm kinda lost on that part :(

ganeshie8 · Answer

okay, since the pulley is small, it must make more rotations right ?

ganeshie8 · Answer

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