Math and environment

For our lungs … thanks to the car… When driving, a vehicle burns the fuel which releases carbon dioxide: it is a greenhouse gas Why is it better to take a bus than a car ? Let’s calculate !!

50 persons want to join a city which is 300 km away… Each person takes his car

All in a bus

A car uses 7 litres of petrol for 100 km

bus uses 35 litres of petrol for 100 km

Volume of petrol needed :

Volume of petrol needed :

3 x 7 x 50 =1050 litres Mass of rejected CO2 :

1050 x 2,4 = 2520 kg

3 x 35 = 105 litres Mass of rejected CO2 :

105 x 2,4 = 252 kg It is ……. times less !!

Ecological house

How can the new ecological house reduce the energy consumption?

Building a traditional house of 100 m² costs about 100 000 euro A new ecological home is 7% more expensive Price for an ecological house of 100 m² :

100 000 + (7/100 x 100 000) = 107 000 € Extra expense :

107 000 € - 100 000 € = 7 000 €

Energy expenditure in a traditional house of 100 m² for one year

350 x 100 x 0,1 = 3500 € Energy expenditure in an ecological house of 100 m² for one year

50 x 100 x 0,1 = 500 €

Energy savings

3500 € - 500 € = 3000 € each year How long to pay off the ecological home? 7000 ÷ 3000 ≈ 2,3 years only

First menu generated 0,5 kg of carbon dioxide

Second menu generated 5,6 kg of carbon dioxide

WHY ?

math et environnement

séance de la commission environnement du collège