Energy transferred to eardrum from sound wave

[kingwinner]

A sound wave with intensity 2x10^(-3) W/m^2 is perceived to be modestly loud. Your eardrum is 6.0 mm in diameter. How much energy will be transferred to your eardrum while listening to this sound for 1.0 min?

P=IA=(intensity)(area)
=2x10^(-3) * (pi (6x10^-3)^2)
=2.2610x10^-7 W

P=delta E/ delta t
=2.2610x10^-7 J/s * 60 s
=1.3572x10^-5 J

But this is not the right answer. I have no idea what I did wrong. Can someone please help me? Any help is greatly appreciated! Thanks!

 

[Dick]

For one thing the diameter is 6mm. Not the radius. Change your pi*r^2 number.

 

[kingwinner]

Thanks for pointing it out! I rarely make this kind of silly mistake