The formula for the volume of a sphere is v=4/3 pi r squared. find the volume of a sphere with a radius of 2cm. use 3.14 for pi. round to the nearest hundredths.

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning