I need help. I have no idea how to start. 'A circular tunnel is used to accelerate elementary particles. The radius of the tunnel is about 4 kilometers. If a particle travels one complete revolution through the tunnel, what distance does it travel?'

Question

anonymous · Answer

The electron is being accelerated at the edge of the circle. Another name for the edge of the circle is the circumference.
In order to calculate the length of the circumference we have the equation:
C=pi*d=pi*2*r

anonymous · Answer

thanks! I understand now.