Question

Сколько понадобится краски,чтобы покрасить поверхность бруса(длина-40 см,ширина-30см,высота-20см),если покрасить 1 кв.дм поверхности нужно 2 г краски?

Answer 1

40см-4дм,30см-3дм,20см-2дм

считаем площадь строн бруса:

2(2*3)+2(4*2)+2(4*3)=12+16+24=52 кв. дм площадб всей поверхности бруса

52*2=104г краски потребуется для покраски бруса

ответ:104г 

Answer 2

Calculating the Amount of Paint Needed

To calculate the amount of paint needed to cover the surface of the given wooden block, we can use the following formula:

Amount of paint (in grams) = Surface area to be painted (in square centimeters) × Amount of paint needed per square centimeter (in grams)

Given: - Length of the block = 40 cm - Width of the block = 30 cm - Height of the block = 20 cm - Amount of paint needed per square centimeter = 2 grams

Calculating the Surface Area of the Wooden Block

First, let's calculate the surface area of the wooden block using the given dimensions. The surface area of the block can be calculated using the formula:

Surface area = 2lw + 2lh + 2wh

Where: - l = length - w = width - h = height

Substitute the given values: - l = 40 cm - w = 30 cm - h = 20 cm

Surface area = 2(40*30) + 2(40*20) + 2(30*20) Surface area = 2400 + 1600 + 1200 Surface area = 5200 square centimeters

Calculating the Amount of Paint Needed

Now, we can use the surface area and the amount of paint needed per square centimeter to calculate the total amount of paint needed.

Amount of paint = Surface area × Amount of paint needed per square centimeter Amount of paint = 5200 square centimeters × 2 grams Amount of paint = 10400 grams

So, to paint the given wooden block, approximately 10400 grams of paint will be needed.