The maximum weight that a rectangular beam can support varies jointly as its width and the square of its height and inversely as its length. If a beam one fourth

foot wide, one third

foot high, and 10 feet long can support 20 tons, find how much a similar beam can support if the beam is two thirds

foot wide, one fourth

foot high, and 11 feet long.

# Need help!?

## Answers (1)

You don't say what help you need, but I suspect that you need to strengthen your math skills. You have to be perfectly prepared in math to study engineering subjects.

Get a ruler in your hands. Measure things until you start to understand how a ruler works. Measure some stuff and figure out where the center is. Say you measure a book and it's 7/8" thick. You look at your ruler and see that every eighth is divided into two sixteenths, so obviously half of 7/8" is going to be 7/16". If you write that out you have 1/2 x 7/8 = 7/16. And you notice that 1/2 is divided into 2/4 and then into 4/8 and so on, so you can convert anything to anything by multiplying all the numbers on top and then all the numbers on bottom.

Other rulers are divided into 10 and 100 parts. But an inch is still an inch, so anything on one ruler can be translated to the other ruler. A half inch on one ruler is 5/10 or 50/100 on the other. An eighth inch is just 12.5 marks when you have 100 marks per inch. A metric ruler divides an inch into 25.4 parts, so a half inch would be 12.7 of those parts. Pretty simple, isn't it? Practice this a bit and people will think you went to wizard school.