OCHEM transition states and reaction rates

[coookiemonste]

Homework Statement

Explain why 2-bromopropane reacts with NaI in acetone over 10^4 times faster than bromocyclopropane. (Hint: examine the transition state for each of the reactions)

Homework Equations

The Attempt at a Solution

I understand this is a sn2 type reaction and therefore is completed in one step. Is bromocyclopropane's transition more sterically hindered than 2-bromopropane?

 

[chemisttree]

Draw the structure for both. Remember to accurately represent the cyclopropate ring. Look at all the angles.