plz answer these two easy questions?

Question

1)if population density at a place is 1000persons/sq.km,how will u express this in persons/sq.metre?

2)what is the trigonometric value of cos30 degree?

Answer 1

In a square kilometer, there are 1 million square meters. Therefore, every 1 person would have 1000 square meters of space. A way to think of this would be to line up every person on one side of the square. Since there are 1000 meters to each kilometer, one person would stand in a 1 meter square, and then you would have a line 1000 people long. Because a square kilometer has another kilometer going in a perpindicular direction the the one in which everyone is standing. Each person would then control the 1000 meters of space running perpindicular to them. I know when you originally look at this equation you are thinking it should come out to 1 person for each square meter, but that's math trying to mess you up.

2. cosine 30 degrees equals .86660. To really explain this to you I need to know if you understand or have learned what the unit circle is?

Thanks

Answer 2

1000 / 1 sq. km = X / 1 sq. metre

1 sq. km = 1,000,000 sq. metres (1000 x 1000)

1000 / 1,000,000 sq. metres = X / 1 sq. metre

X = 0.001 people per sq. metre


cos 30 degrees = the square root of three divided by two

which is approx. 0.866

Answer 3

1)Divide by 1,000

2) Exact = sq rt 3 / 2 = .86

Answer 4

1) There are 1000 meters in a kilometer so it would be one person per square meter.

Answer 5

1) others have answered

2) √3 / 2 is the exact answer. This is also 0.866.........

Answer 6

1) 0.001person/sq. metre
because 1 sq. km = 1000000 sq. metre
2)0.866025403~~0.87