Post a New Question

algebra

posted by on .

the weight of a symetry ball varies directly with the cube of it's radius a ball with the radius of 2 inches weighs 5.60. find the weight of a ball with a 3 inch radius

  • algebra - ,

    weight = k r^3 , where k is a constant
    when r = 2, weight = 5.6
    5.6 = k(2^3)
    k = 5.6/8 = .7

    so weight = .7r^3
    when r = 3
    weight = .7(27) = 18.9

    or ... just use a ratio

    w/5.6 = 3^3/2^3
    w = 5.6(27/8) = 18.9

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question