In unknown liquid: G-F'=ρ gV liquid discharge-②
From ① ②, the density of liquid: ρ liquid =G? f’G? Fρ water;
(2) Experimental steps: ① Tie pebbles with fine iron wire, and pour proper amount of water and liquid into two beakers respectively;
② Measure the gravity g of pebbles with a spring dynamometer;
(3) measuring the pulling force f of small stones immersed in water with a spring dynamometer;
(4) measuring the tensile force F' of the pebbles immersed in the liquid B with a spring dynamometer;
As shown in the figure below: