Thursday, April 20, 2006

Marielou's Surface Area and Volume Problems

hope this isn't too late!!!! (ill post it anyways =)

*i know my picture isn't accurate with the #'s given but.... i hope you get what i mean
Problem 1 (Easy)
1. How much cement is needed to build a sidewalk that is one thousand, one hundred twenty metres long, four metres wide and fifty centimetres thick? Round your answer to the nearest cubic metre.

to figues out this question you would have to find the volume

(oh yea.. color coded it so it would be easier)

to find volume you multiply length(L) times width(W) times height(H)
= 1120x4x0.5
= 2240 m3

so the answer is 2240 m3 (of cement?)

Problem 3 (easy)
3. If you have five 5 cm by 5 cm x 5 cm aluminum cubes and superglue them together in a row, what is the surface area of the resulting shape made by the five cubes?

hmmm... ill post a picture =)

to finde the TSA you have to figure out the area of all the sides of your rectangular prism. since your width is made up of 5, 5cm squares, you could add them you together so that you only have one number for your width instead of 5.
so it would be: 5cm + 5cm + 5cm + 5cm + 5cm= 25cm
so the value of your width is now just one number 25 cm.

now to solve! (ill post another picture)

now to add all of the totals together:
250 cm2 + 250 cm2 + 50 cm2
550 cm2

so, the TSA is 550 cm2 (i hope?)

ohkays so now im done! hope i did it right?...... wells that it i guess!! =)

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