A proton and an alpha particle start from rest in a uniform electric field then
ID: 1685055 • Letter: A
Question
A proton and an alpha particle start from rest in a uniform electric field then the ratio of time of flight to travel same distance in the field is?Explanation / Answer
We know that F = m a and F = E q So that we have E q = m a ==> a = E q / m The charge of proton q1 = e = 1.6 x 10^-19 C The charge of alpha particle = q2 = 2q1 = 3.2 x 10^-19 C mass of alpha particle m2 = 4 m1 When particle starts from rest, the distance traveled in time t is d = 0.5 a t^2 So that we have d1 = d2 0.5 * E * (q1 / m1) t1^2 = 0.5 * E * (2q1 / 4m1) t2^2 t1^2 = t2^2 / 2 ==> t1 / t2 = [ 1 / 2 ] ^1/2 = 0.7071