Posted by julie on .
A light spring of constant k = 170 N/m rests vertically on the bottom of a large beaker of water. A 5.70 kg block of wood (density = 650 kg/m3) is connected to the spring and the massspring system is allowed to come to static equilibrium. What is the elongation, ÄL, of the spring?
im using the equation of the spring constant... F=kx F being Bweight. and i keep coming up with the wrong answer. please help me!!!

physics help please... 
Damon,
volume of wood = (5.7/650) m^3
difference in density = 1000650 = 350 kg/m^3
net force up = 350 (5.7/650)(9.81) = 30.1 N
F = k x
30.1 = 170 x
x = 30.1/170 = .177 meter 
physics help please... 
julie,
why is the difference in density 350? where does the 1000 come from?

physics help please... 
Damon,
water density = 1,000 kg/m^3
close enough :) 
physics help please... 
bobpursley,
the 1000 kg/m^3 is the density of water.

physics help please... 
Damon,
I used the difference in wood and water density to get the net buoyancy.