# trigonometry

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A wheel with a 21-inch diameter is turning at the rate of 58 revolutions per minute. To the nearest inch, what is the velocity of a point on the rim in inches/minutes?
3879 inches/minutes

• trigonometry -

10.5 in * 58 rev/min * 2 pi radians/rev = I get 3826 in/min

• trigonometry -

By the way, earlier I notice you were looking for a calculator:

http://www.mathsisfun.com/scientific-calculator.html

• trigonometry -

yes,..the guy was teaching me how to do this problem
[pi,3pi/2];tan s=1
can you help..i need to use this link to figure out this problem..please guide me through:)

• trigonometry -

on calculator
type in the number 1
click atan
click +
click Pi
click =

• trigonometry -

so..5pi/4
thank you very very much..i just have one LAST problem i need help with

A pulley of radius 11cm rotates 5 times in 64 seconds. Find the angular velocity of the pulley.
thnks again

• trigonometry -

i think you have to use the formula
w=pi/t

maybe..

• trigonometry -

Yes, 5 pi/4
You could have seen that from the start because you probably know that the tan of 45 deg (Pi/4 radians) is 1 and pi/4 + pi = 5 pi/4
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radius has noting to do with this
5 * 2 pi radians / 64 s

.49 I mean

• trigonometry -

so 5pi/32

thank you soo much!!!!