I think it is equal for your question
Answer:

Explanation:
Generally the workdone in moving the proton is mathematically represented as

Where 
So

Here
is the velocity at A with value 50 m/s
So


Also

Here
is the velocity at A with value 
=> 
=>
So


Now this workdone is also mathematically represented as

So

Here 
So


Generally proton movement is in the direction of the electric field it means that 
So

Answer: (a) t1 = omega1/alpha
(b) theta1 = 1/2 * alpha*theta1^2
(c) t2 = omega2/5*alpha
Explanation: see attachment