An electron moving with a velocity of 5×104 m s-1 enters into a uniform electric field and acquires a uniform acceleration of 104 m s–2 in the direction of its initial motion.
(i) Calculate the time in which the electron would acquire a velocity double of its initial velocity.
(ii) How much distance the electron would cover in this time?
given
Initial velocity u = 5x104 m s-1
And acceleration a = 104 m s-2
(i) According to the given question, the final velocity v = 2u
We need to find the time, t =?
V = u+ at
2u = u +(104 ms-2 ) × t
u = 104 ms-1 × t
t = u / 104 m s-1
t = (5x104) / 104
=5s
(ii) t=5s, a=104 ms-2, u=5x104ms-1 s=?
s=ut + at2
s = (5 x104) x5 +1/2(104) x (5)2
s = 25 x104 + 25/2 x (104)
s = 25 x 104 +12.5 x (104)
s = 37.5x104 m