Fermi cy alles

a) What about the water that each of the students coming to Spain uses in one year?

On average, everyone of us use approximately 150 liters of water per day. This water is used:  Toilet flushing 30%  Personal washing - baths and taps 21%  Personal washing - showers 12%  Clothes washing 13%  Washing up 8%  Outdoor 7%  Other 5%  Drinking 4% So in one year it will use (150 * 365 = 54750 L) 54750 L of water.

b) How many drops of water are in a glass of 250 cm続?

By measuring with the dropper how many drops of water is 1cm3 we find that 1cm3 contains 23 drops.

So in 250cm3 Number of drops = 250 * 23 = 5750 the number of drops that exist is 5750

c) How much a person of 78 years has drunken in his life? How many bath tubes could be filled with it?

If a person drink an average of 2L each day then in one year water drunken = 2 * (365,25) = 730,5L so in the 78 years of his life he has drunken (730,5 * 78 = 56.979) 56979 L of water

A bath tube with dimensions: Height: 20cm Width : 40cm Length : 150cm has a volume =0,2 * 0,4 * 1,5 = 0,12m3 = 120L number of bath tubes filled = 56989 / 120 = 475 So with the water that a person of 78 years has drunken in his life we can fill approximately 475 bath tubes.

d) What about weight of this load if all water carriers were full?

If the height of the motorcycle is 1m we can say that the height of each water carrier is 0,5m and if the length of the motorcycle is 1,4m we can say that the radius of each water carrier 0,15m.

So V = π * (0,15)2 * 0,5 = 0,035m3 =35L of water.

Since the density of the water 1kg/L Mass = d * V = 1 * 35 = 35kg The mass of each water carrier is 35kg and the motorcycle on the photo carries 10 bottles of water so the total mass that it carries is equal to 350kg

The average height of a man in the decade of 1910 according to the graph is: Av. Height = (168 * 2 + 167,5 + 167 * 3 + 166 * 2) / 8 = 167cm and the average width of a man in this period is approximately 40cm In the image we have a barrel of the shape of cylinder which have a radius equal to the height of a man. So radius = 1,67m

Then if the width of the barrel is equal to the width of seven persons then: Width of barrel = 7 * (0,4) = 2,8m So the volume of this barrel is: V = π * (1,67)2 * 2,8 = 24,5m2

How many crates of mineral water can be transported in this huge shopping trolley?

If the dimensions of this volkswagen car is: Height of the car: 1.5m ,

Length of the car: 4m ,Width of the

car: 1.7m Then for the shopping trolley : Height of shopping trolley: 1,5m

Width of shopping trolley:

1.7m Length of shopping trolley : (480/350) * 4 = 5,5m So the volume of it is : Volume = 1,5 * 1,7 * 5,5 = 14 m3 And if the dimensions of a crate of mineral water which contains 24 bottles of capacity 250ml is : Height : 28cm

Length : 40cm

Width : 30cm

Then its volume is : V = (0,28)(0,4)(0,3) = 0,034 m3 Number of crates = 14 / 0,034 = 412 In this huge trolley we can transport approximately 412 crates of mineral water.