A thread is being pulled off a spool at the rate of 573 cm p

A thread is being pulled off a spool at the rate of 57.3 cm per sec. Find the radius of the spool if it makes 141 revolutions per min. Round to two decimal places as needed.

Thank you in advance !

Solution

Every min, 141 revs

So, for each revolution ,it takes
60/141 seconds

60/141 sec/revolution

Now, multiply this to 57.3 cm per sec to find the
cm/revolution :

60/141 * 57.3

24.3829787234042553 cm per revolution

So, circumference = 24.3829787234042553 cm

Now, using this, we get radius...

2pi * r = 24.3829787234042553

r = 24.3829787234042553 / (2pi)

r = 3.88 cm -----> ANSWER