A golf ball is approximately spherical with a radius of about 2 cm. Spaceship Earth is approximately a sphere of radius of 27 m. About how many golf balls would it take to fill Spaceship Earth?
A) 20,000,000
B). 200,000,000
C). 2,000,000,0000
Answer: The volume V of a sphere is given by V = (4/3)πR3 where R is the radius. Substituting R = 2 cm into this formula gives the volume of the golf ball to be about 33.51 cm3. Substituting R = 2700 cm gives the volume of Spaceship Earth to be about 82,448,000,000 cm3.
Dividing the volume of Spaceship Earth by the volume of a golf ball yields approximately 2,460,000,000. However, even the tightest packing of spheres leaves about 1/4 of the space unfilled, so the number of golf balls that we could pack into Spaceship Earth would be 3/4 of 2,460,000,000 or about 1,845,000,000. Therefore, answer C (2 trillion) is the closest approximation to the number of golf balls that could fit in Spaceship Earth.
