size of length

Question

There are 2 balls that are both 50 cm diameter and they have a 2cm gap between and they have a belt around them how long is the belt?

Answer 1

Dylan,

Divide this problem into three pieces:

 

First, the length of the belt wrapped around the first ball is one-half its circumference. (This is because both balls are the same size.) So this length of belt will be 0.5 x 2 x pi x 25cm = 25pi cm.

 

Second, the belt wrapped around the second ball is the exactly same length = 25pi cm.

 

Finally we have the length of the belt between both balls. Take this as opposite sides of a rectangle, whose lengths include the radius of both balls + 2cm gap added for each side of the rectangle = 2 x (25cm + 25cm + 2cm) = 104cm.

 

Add these three elements together:

(25pi cm) + (25pi cm) + 104cm

50pi cm + 104cm

 

≈ 157.08cm + 104cm ≈ 261.08cm (rounded to the nearest hundredths.)

 

Hope this helps!

 

Neal