The side length of a square is 5cm. The side length of a square is increased by 10%. How many percent is its area increased

The side length of a square is 5cm. The side length of a square is increased by 10%. How many percent is its area increased

5×（1＋10%）＝5.5
（5.5×5.5－5×5）÷（5×5）＝0.21＝21%
Its area has increased by 21%

How to calculate the side length of a square? How to calculate the side length when the known area is 100 square centimeters?

If the area of the square is equal to the side length ^ 2 and the side length is 10 cm, then the perimeter is 4 * 10 = 40 cm

A cylindrical container with a bottom area of 100cm2 and a height of 10cm,
When the metal block is immersed in the water and is still, the indication of the spring dynamometer is 4.8n. After the metal block is slowly taken out, the pressure of the container on the table is 11.4n. Calculation: (1) the gravity of the container (2) the buoyancy of the metal block (3) the density of the metal block

1. Quality of water in the container:
M water = ρ water v = ρ water sh = 1 × 100 × 10 = 1000g = 1kg
The pressure on the table is 1200pa, i.e. P = f / S = gtotal / s
The result is: gtotal = PS = 1200 × 100 × 10 ^ - 4 = 12n
Gwater = mwater g = 1 × 10 = 10N
So: G container = g total - g water = 12 - 10 = 2n
2. F floating = g row = 12n-11.4n = 0.6N
3. G-F pull = f float
That is: ρ gv-4.8 = 0.6, and: v = m discharge / ρ water, m discharge = 0.6/10 = 0.06kg
The results show that ρ = 5.4/g × 0.06/1000 = 0.9 × 10 ^ 3kg / m ^ 3
I don't know what to ask