Determining the Probability of a Nuclear Fusion Reaction: Solve Here!

[jim mcjimbers]

Homework Statement

In a particular nuclear reaction, a neutron moving at 3.6×105ms−1 has a 70% chance of initiating a nuclear fusion reaction. Which of the following options is a possible probability of a neutron moving at 2.2×105ms−1 initiating the same nuclear reaction?

I wouldn't be asking this if I really didn't know where to start. I don't even know which formula to use or how to begin solving this. Any help would be greatly appreciated, thanks!

 

[mfb]

Where are the options?
Are there any reactions where you know if the cross-section is higher or lower for higher/lower speeds?

 

[jim mcjimbers]

Where are the options?
Are there any reactions where you know if the cross-section is higher or lower for higher/lower speeds?

Yeah, the options are
A) 70%
B) 0%
C) 82%
D) 56%