Results 1 to 2 of 2

Thread: Calculate Volume of a Submarine Shape

  1. #1
    New Member
    Join Date
    Mar 2011
    Posts
    4

    Calculate Volume of a Submarine Shape

    Just need some minor help here AND someone to check my thinking.

    Here's the problem:
    What is the volume of the following submarine model?

    WHAT I KNOW:
    Front front rounded part = radius of 3 inch/ length (height) of 3 inch
    cylinder body = radius of 3 inch/ length (height) of 12 inches
    tail cone part = radius of 3 inches/ length (height) of 4 inches

    volume formula for front rounded part = hemisphere = volume of sphere/ 2 = 4/3 * pi * r (cubed)/2
    v sphere = 4/3 * 3.14159 *3 (cubed)
    v sphere = 1.33333 * 3.14159 * 27
    v sphere = 113.09 inch (squared)
    v hemisphere = 113.09 inch/2 = 56.545 inch (squared)

    volume formula for cylinder body = pi * r (squared) * height
    v cylinder = 3.14159 * 3 (squared) * 12
    v cylinder = 3.14159 * 9 * 12
    v cylinder = 339.2917 inch (cubed)

    volume formula for tail cone = 1/3 * pi * r (squared) * Height
    v cone = 1/3 * 3.14159 * 3 (squared) * 4
    v cone = .33333 * 3.14159 * 9 * 4
    v cone = 37.699 inches (cubed)

    TOTAL volume of the mini sub = volume of hemisphere + volume of cylinder + volume of tail cone
    113.09 + 339.2917 + 37.699 = 490.08 inches
    HERE'S QUESTION ONE.....is the answer in cubic inches OR square inches? AND are my calculations correct?

    HERE'S QUESTION TWO .....If one inch of the model represents 20 feet in the actual sub, what is the volume of the actual sub?
    I believe that this is a proportion problem. Height of hemisphere = 3 in/ height of cylinder = 12 inches/ height of cone = 4 inches.
    Total height of model = 19 inches. Total volume of model = 490.08

    19 inches * 20 feet = 380 feet (actual sub length)
    490.08/ 19 inches = 25.79 volume per inch
    25.79 * 12 = 309.48 volume per foot
    309.48 * 380 = 117,602 total volume (actual sub)

    CORRECT THINKING?
    WRONG?

    Pls comment and advise.
    Thank you!

  2. #2
    Elite Member
    Join Date
    Feb 2004
    Location
    Ottawa, Ontario
    Posts
    16,333
    I'm just an imagination of your figment !

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •