When adding weights to the right, you should follow the order of "from big to small". If you add more minimum weight and remove less, you must balance it by adjusting the line code, which is abbreviated as "big first, then small, and then code".
Quality of sweet potato: m = 50g+10g+3.6g = 63.6g;
The volume of sweet potato V=80ml-20ml=60ml.
Density of sweet potato: ρ = mv = 63.6g60cm3 =1.06g/cm3 =1.06x103kg/m3.
(2) Adjust the density of the brine so that the sweet potato is suspended in the brine, and then measure the density of the brine with a densimeter.
So the answer is: (1) move the balance nut to the right; Remove the minimum weight, and then move the code; 63.6; 60; 1.06× 103 kg/m3
(2) Put the sweet potato into a big teacup with enough water, gradually add salt into the big teacup and stir. When the sweet potato is suspended, the density of brine is measured with a densimeter, which is equal to the density of sweet potato.