Centripetal Force; calculating speed

[Macrowave]

Homework Statement

A wet towel, of mass 0.65 kg, travels in a horizontal circle of radius 26cm in the spin cycle of a washing machine. The frequency of rotation is 4.6Hz.

a)Name the force causing the centripetal acceleration. What object exerts that force?
b) What is the speed of the towel?
c) Determine the magnitude of the centripetal force on the towel.

Homework Equations

Fc=4pi^2mrf^2
Fc=(mv^2)/r

The Attempt at a Solution

I tried plugging in the values into the first equation and got 30.69 then i tried putting it into the second equation to solve for velocity but got 3.5 and the answer is 7.5. Someone please help me on this question.

 

[SammyS]

Probably some algebra error or arithmetic mistake.

Show us some intermediate steps.

 

[supratim1]

equations are correct.

 

[J.Jobs]

4.6hz means that the towel travels 4.6 of its circumference per second.

v=4.6(2piR)cm/s
=9.2 x 26 x pi cm/s
= 751cm/s
= 7.51m/s

 

[supratim1]

which is correct answer!