Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

How many tennis balls can you fit in a car?

  • 24-02-2014 1:28pm
    #1
    token101
    Registered Users, Registered Users 2 Posts: 3,050 ✭✭✭


    I have a college project which I could really use some help with. Basically, I need to fill a car which is 75.6 cu. ft. full of balls (ie tennis balls or the balls you'd find in a kids ball pit). The balls are 5cm in diameter. How many do I need?

    I have absolutely no idea how to calculate this! It's for a marketing assignment where I have to budget for this stuff so any help greatly appreciated.


Comments

  • #2
    Morbert
    Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    Using the Kepler Conjecture, the maximum number of balls you will be able to fit is

    74% of the volume of the car / volume of a tennis ball

    (.74)*75.6/0.002311338 = 24,204 balls

    This answer is a good first approximation.


  • #3
    Carawaystick
    Registered Users, Registered Users 2 Posts: 8,779 ✭✭✭Carawaystick


    As a first step, you need to convert your measurements to the same system, either imperial or metric.
    I'd heartily suggest you use the metric system.

    so you have the volume of a car in metric
    get the volume of a tennis ball

    get the volume of a cube of 5cm size

    divide the car volume by the tennis ball volume and
    also by the cube volume

    this will give you an upper and lower limit

    figure out how many balls you can fit together and how much empty space you'll have left over -- the Kepler conjecture is a good estimate, and then there's gonna be less as there will be awkward shapes in a real car.


  • #4
    Labarbapostiza
    Banned (with Prison Access) Posts: 963 ✭✭✭Labarbapostiza


    token101 wrote: »
    I have a college project which I could really use some help with. Basically, I need to fill a car which is 75.6 cu. ft. full of balls (ie tennis balls or the balls you'd find in a kids ball pit). The balls are 5cm in diameter. How many do I need?

    I have absolutely no idea how to calculate this! It's for a marketing assignment where I have to budget for this stuff so any help greatly appreciated.


    One. If it's a marketing assignment, the first rule of marketing is 'what you see is not necessarily what you'll get.' If you can get away with creating the illusion the car is full of balls, that's what you do.

    Two. If you actually have to fill the cars with balls. Then you use Morberts solution. .......But why anyone would want to actually fill a car with actual tennis balls is beyond me. How many balls you need to create the illusion the car is full of balls, could be an interesting if not more interesting mathematical problem, than the original ball volume problem.


Advertisement