Hey guys I'm in a band and we want to start using an Acoustic guitar in several songs, but the whole thing resonates whenever the drummer hits a tom or bass drum.. It pretty much makes the acoustic unplayable. I assume this is a common problem and there is a very simple fix.

P.S. Sorry if this is a common problem, I had no idea how to word the forum search.
use a PA would be my bet, but Ive got the same problem in my band, we had to start using my electric drums.
Burswood Acoustic
Squier Affinity Strat
Fender Tele Deluxe
Ibanez Jetking bass
Marshall MG30DFX
Peavey max 158 bass amp
Fender Bassman 250
1979 Carvin of some sort
And some pedals
eqing helps, too. Since you said it feeds back whenever the drummer hits a tom or the bass drum you're likely getting bass frequency feedback. Also, are you using a PA or an amp for your acoustic? electric or acoustic amp? If you're using an electric amp then that's your problem.

If you're using a PA then get a Direct Box/Pre-amp like the LR Baggs PADI or the Fishman Pro Platinum EQ. both of these units have feedback reduction controls like notch filter and phase inversion.

Dr. Z Stangray
G&L ASAT Classic (Ron Kirn Custom T-Style coming soon! ronkirn.com)
Keeley 4 Knob Compressor
Taylor 314ce
Becareful those feedback busters can **** up the sound hole real quick, as I learned the hard way on my Ibanez