1. The problem statement, all variables and given/known data A large 3.00×10^4 L aquarium is supported by four wood posts (Douglas fir) at the corners. Each post has a square 3.80 cm x 3.80 cm cross section and is 80.0 cm tall. By how much is each post compressed by the weight of the aquarium? 2. Relevant equations deltaL = F*L_0/(Y*A) Y (for Douglas fir) = 1 * 10^10 N/m^2 3. The attempt at a solution This seems very straight forward, I just need to determine F. F= ma = m(aquarium)g but, what is the mass of a 3.00×10^4 L aquarium? once I determine that, I figure it'll just be: deltaL = ( m * 9.8 * .8)/(.144 * 10^10) meters => 5.44*10^10*m meters How do I find m ?? Thanks for the help!