The mass on the spring is bouncing.
We would call it a wave-like motion, except that it all stays in the same place. But, just like a wave, moving from the highest position to the lowest position
is one-half of a full wiggle.
(The other half consists of moving from the lowest position back up to the
highest position, where it started from.
So, half of the wave-like motion takes 0.6 seconds.
A full cycle of the wave motion ... the actual period of the bounce,
is double that much time . . .
1.2 seconds.
Answer:
a)
is the speed of each proton
b) 
Explanation:
Given:
radius of path of motion, 
we know charge on protons, 
magnetic field strength, 
we've mass of proton, 
a)
From the equivalence of magnetic force and the centripetal force on the proton:



where:
v = speed of the proton

is the speed of each proton
b)
Now the centripetal force on each proton:



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