Question
Thu June 28, 2012 By:
 

An electron is moving with a velocity of 5*10^4 ms^-1.When an electric field is applied,it produces an acceleration of 10^8 ms^-2.Calculate the following. (a) Time in which velocity gets double? (b) Distance travelled during this time interval?

Expert Reply
Thu June 28, 2012
Initial velocity of electron, u = 5 x 104 m/s
acceleration, a = 108 m/s2
 
Using first equation of motion,
final velocity, v = 2u
 
v = u + at
2u = u +at
t = u/a = 5 x 10-4 s
 
Distance travelled in this time interval be s
using 2nd equation of motion.
 
s = ut + (1/2)at2
s = 37.5m
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