Question

An electron travelling with a speed of 5 x 103 m/s passes through an electric field with an acceleration of 1012 m /s2. How long will it lake for the electron to double its speed? What will be the distance covered by the electron in this time

Answer 1

Distance = speed * time
= 5 * 10^3* 5 * 10^-9
= 25 * 10^-6 m

Answer 2

Answer:

The distance covered by the electron in this time will be $25\times10^{-6}\ m$

Explanation:

Given that,

Speed $v=5\times10^{3}\ m/s$

Acceleration $a=10^{12}\ m/s^2$

Let us consider initial velocity = u

Final velocity = 2 u

Using equation of motion

$v= u+at$

$t= \dfrac{v-u}{a}$

$t= \dfrac{2u-u}{a}$

$t= \dfrac{u}{a}$

$t= \dfrac{5\times10^{3}}{10^{12}}$

$t= 5\times10^{-9}\ s$

The distance is the product of the speed and time.

The distance covered by the electron in this time will be

$D=v\times t$

$D=5\times10^{3}\times 5\times10^{-9}$

$D= 25\times10^{-6}$

Hence, The distance covered by the electron in this time will be $25\times10^{-6}\ m$