(1) Measure L0 and L 1 after the lever is balanced.

(2) Immerse the stone in water, adjust the hanging position of the stone to balance the lever and measure L2.

(3) Calculate with the above formula;

According to the balance condition of lever:

Gram iron L0 = gram stone L 1

Then g stone =G iron l0l1;

Gram iron L0= (gram stone-rho water gV stone) L2

Get V stone =G stone L2? Gram iron l0 rho water gL2 = gram iron L0(L2? L 1)L 1L2gρ water;

ρ stone =m stone v stone =G iron L0L 1gG iron L0(L2? L 1)L 1L2gρ water =L2ρ water L2? L 1。

So the answer is: (1)ρ stone =L2ρ water L2? L 1。

(2)a, measure L0 and L1after the lever is balanced;

B, immerse the stone in water, adjust the hanging position of the stone, balance the lever, and measure L2;

C. Calculate the density of the stone with the measured data.