[tarsis20]

I am having problems with this exercise since I don't know how to really approach it.

Here is the problem:

The population density of worms in a particular field is 25 worms per cubic meter of soil. How many worms would there be in the top meter of soil in a field that has dimensions of 1.00 km by 1.5 km.

I just only know this: 1.00km----> 1.00 x 10^3 meters ------> 1.00 x 10^27 cubic meters
                             1.5km-----> 1.5 x 10^3 meters--------> 1.5 x 10^27 cubic meters

and now I am lost?? What do I have to do??? What I did is wrong??

Please explain me how to approach it.

Thanks all

[Borek]

You have to find volume of a cuboid 1km x 1.5km x 1m. Convert everything to meters first, then use formula for the cuboid volume.

[WorkEthic]

To do this type of problem, it is important that you have a sound understanding of dimensional analysis.  Learn it well now, because it will be a cardinal concept in almost every science course you take.
I will walk you through this problem, since it is relatively simple.

1) Find the volume of the cuboid:
(1.5 km^3) x (1000m/1km) x (1000m/1km) x (1000m/1km) = 1.5e9 m^3

2) It is given that there are 25 worms per cubic meter of soil, so simply multiply:
(25 worms) x (1.5e9 m^3) = 3.75 x 10^10 worms