Question

A large ball 2 m in radius is made up of a
rope of square cross section with edge
length 4 mm. Neglecting the air gaps in
the ball, what is the total length of the
rope to the nearest order of magnitude?​

Answer 1

Explanation:

radius of rope is 2 m

edge of cross section lenght is (4mm)^2=

16×10^-6

volume of ball=4/3πr^3=area of cross section

therefore

16×10^-6= 4/3×3.14×2×2×2

=2×10^6

therefore length is 2×10^6~10^6m~10^6Km