Question

find A flat rectangular roof measures 7.5 m by 4 m; 12 mm of rain falls on the roof. a Find the volume of water on the roof. Express your answer in i cm' and ii m'. Find the mass of water that falls on the roof if 1 cm³ of water has a mass b of 1 gram. Express your answer in kilograms.​

Answer 1

12 mm * 1 m / 1000 mm = 1.2 * 10^-2 meters or 1.2 cm

water vol = 7.5 m * 4 m * 1.2 *10^-2
= 36 * 10^-2 m^3 = 0.36 m^3

0.36 m^3 * (100 cm/m)^3 = 0.36*10^6 = 360,000 cm^3
(which is 360,000 grams or 360 kg

Answer 2

I said 360 kg

Answer 3

a)
i) Volume of water in cm³ = (7.5 m x 4 m x 12 mm) x 10 cm/m x 10 cm/m x 1 cm/mm = 3600 cm³
ii) Volume of water in m³ = (7.5 m x 4 m x 12 mm) = 0.36 m³

b) Mass of water in g = Volume of water in cm³ x 1 g/cm³ = 3600 g
Mass of water in kg = 3600 g ÷ 1000 g/kg = 3.6 kg

Answer 4

You are correct in converting 12 mm to meters and centimeters and calculating the volume of water on the roof in cubic meters and cubic centimeters. However, your calculation for the mass of water is incorrect. One cubic meter of water is equal to 1000 liters or 1000 kilograms, so the mass of water on the roof in kilograms is:

Mass of water in kg = Volume of water in m³ x 1000 kg/m³ = 0.36 m³ x 1000 kg/m³ = 360 kg

Therefore, the correct answer for the mass of water that falls on the roof is 360 kg.

Answer 5

I apologize for the mistake, and you are correct that you calculated the mass of water correctly as 360 kg. Thank you for pointing that out.