Questions below

Question

1) A barrel in the shape of a cylinder is cut half lengthwise to make a water tough for horses. Does the expression:

 

*pi(1/2r)squared 

 

represent the volume of water that the water trough holds? Explain why or why not?

 

*pretend that the "pi" in the equation is the actual "pi" symbol & the "squared" in the equation is an exponent above the parenthesis. Thanks!

 

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2) The barrel in problem one is five feet long and the radius of its base is 1.5 feet. How much water will the water trough hold? Use 3.14 for pi, and round to the nearest whole cubic foot

 

 

THANKS FOR ANSWERING! :D

 

Answer 1

Volume of cylinder: pi(r²)h so Volume of the trough (sp!) is ½(pi)(r²)h.  Your version of the one half is in the wrong place, because it will be squared giving ¼ as an erroneous factor.

 

Use the correct formula & plug in the numbers. As always, I comment that using 3.14, an obviously inferior value of pi, introduces needless inaccuracy.  It's preferable to use 3.1416, at least, or even better, the pi value build into most calculators, and then round off.  (But some teachers are slow to get with it in the era of fancy calculators.)

 

Remember to state not only the decimal answer, but its units, namely cu. ft.