A flat rectangular roof measures 7.5m by 4m,12mm of rain falls on the roof.

(a)find the volume of water on the roof.express your answer in centi-cubic metre and cubic metre.
(b)find the mass of water that falls on the roof if 1centi-cubic metre of water has a mass of 1gram.express your answer in kilogram

a. V = L*W*h = 750*400*1.2 = 360,000 cm^3.

V = 7.5*4*0.012 = ___ m^3.

b. 1g/cm^3 * 360,000cm^3 = ___ grams = ___ kg.

Excellent answer, well-done

The working but a great work

(a) To find the volume of water on the roof, we can use the formula Volume = Length x Width x Height. In this case, the length and width are given as 7.5m and 4m respectively, and the height is the amount of rainfall, which is 12mm.

First, let's convert 12mm to meters. Since 1 meter is equivalent to 1000mm, we can divide 12mm by 1000 to get 0.012m.

Therefore, the volume of water on the roof is:

Volume = 7.5m x 4m x 0.012m = 0.36 cubic meters

To express this answer in centi-cubic meters, we need to convert cubic meters to cubic centimeters. Since 1 cubic meter is equivalent to 1,000,000 cubic centimeters, we multiply the volume by 1,000,000:

0.36 cubic meters x 1,000,000 = 360,000 cubic centimeters

So, the volume of water on the roof is 0.36 cubic meters or 360,000 cubic centimeters.

(b) To find the mass of water that falls on the roof, we're given that 1 centi-cubic meter of water has a mass of 1 gram.

Using the volume of water we calculated in part (a), which is 360,000 cubic centimeters, we can find the mass by multiplying it by 1 gram:

Mass = 360,000 grams

To express this answer in kilograms, we need to convert grams to kilograms by dividing it by 1000:

Mass = 360,000 grams / 1000 = 360 kilograms

So, the mass of water that falls on the roof is 360 kilograms.

To find the volume of water on the roof, we need to multiply the area of the roof by the depth of the rainfall.

First, let's convert the measurements to meters:
Length = 7.5 m
Width = 4 m
Rainfall depth = 12 mm = 0.012 m

(a) Volume of water on the roof:
Volume = Area × Depth

Area = Length × Width
Area = 7.5 m × 4 m = 30 m²

Volume = 30 m² × 0.012 m = 0.36 m³

To convert the volume to centi-cubic meters and cubic meters:
1 cubic meter (m³) = 1000000 centi-cubic meters (cm³)
Therefore, 0.36 m³ = 0.36 × 1000000 cm³ = 360000 cm³

Therefore, the volume of water on the roof is 360000 cm³ or 0.36 m³.

(b) Mass of water on the roof:
Given that 1 cm³ of water has a mass of 1 gram.

Mass = Volume × Mass per unit volume

Mass = 360000 cm³ × 1 g/cm³ = 360000 g

To convert grams to kilograms:
1 kilogram (kg) = 1000 grams

Therefore, 360000 g = 360000 ÷ 1000 kg = 360 kg

Therefore, the mass of water on the roof is 360 kg.

i don't understand

i don't understand sorry for the first post