A flat belt is wrapped around two pulleys of diameter 10cm and 16cm seperated by a distance of 26cm as shown below.
Find the exact length of the belt.
- Is this the distance between the centres?
- Is this the clear space between the pulleys?
I've attached a correct construction of the inner common tangent of 2 circles.
You are dealing with 2 similar right triangles. The ratio of distances of these triangles depends of the ratio of the two radii.
Let R be the radius of the larger pulley.
Let s be the smallest distance between the edges of the pulleys (r+s+R = distance be pulley centers).
Let be the acute angle where the belts 'intersect' -- theta in RADIANS.
Substitute your specific values into the equation.