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**. Homework Statement**

A block oak weighs 90 N in air. A piece of lead weighs 130 N in water. The two weigh together 100N in water. Calculate the relative density of the wood.

## Homework Equations

F=mxg

F(archimedes)= density x Volume x g

## The Attempt at a Solution

F (g)oak = 90 N

F= mxg

m= 90N/9.81 m/s2

m= 9.17 gram

Oak in water = 130-100 N =30 N

Farchimedes oak = 90N-30N =60N

60N =1000kg/m3 x V x 9.81 m/s2

V=60N/9810

V=0.00611

Now that I have calculated V I can find density

rho = 9.17kg/ 0.00611 m3

density = 1499

Relative density is 1499 /1000 kg/m3 = 1.499

But the correct answer is 0.75

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