Question

A sience teacher uses an overhead projector to display a diagram of a pulley sytem. the actual diagram is 6'' by 7.2''. The image projected onto the wall is 4' 2'' by 5'' what is the scale factor of the projection

Answer 1

25/36, or .694444

Explanation:

First, let's convert 6" to inches.

That gives us 72. After we convert 4'2" into inches, we get 50.

This means that the diagram goes from 72 inches wide to 50. Put this into a proportion to find the scale factor:

50/72 = 25/36 = .6944444