An electron moving parallel to the x axis has an initial speed of 4.10 106 m/s at the origin. Its speed is reduced to 1.76 105 m/s at the point x = 2.00 cm.

Required:
a. Calculate the electric potential difference between the origin and that point.
b. Which point is at the higher potential?

Respuesta :

Answer:

a

  [tex]V = -47.65 N/C[/tex]

b

At the origin

Explanation:

From the question we are told that

   The  initial speed is  [tex]v_1 = 4.10 *10^{6} \ m/s[/tex]

    The  speed at (x = 2.00 cm) is  [tex]v_f = 1.76 *10^{5} \ m/s[/tex]

   

Generally the electric potential difference is mathematically represented as

    [tex]V = \frac{W}{q}[/tex]

Here W is the  work-done which is mathematically represented as

    [tex]W = K_f - K_i[/tex]

Here  [tex]K_f[/tex] is the kinetic energy at  x =  2.00 cm mathematically expressed as

        [tex]K_f = \frac{1}{2} * m* v^2_f[/tex]

and  

       [tex]K_i[/tex] is the kinetic energy at origin  mathematically expressed as

        [tex]K_f = \frac{1}{2} * m* v^2_i[/tex]

So

    [tex]V = \frac{1}{q} [ \frac{1}{2} mv_f^2 - \frac{1}{2} mv_i^2][/tex]

    [tex]V = \frac{m}{2q} [v_f^2 - v_i^2][/tex]

Here m is the mass of electron with value [tex]m = 9.1*10^{-31} \ kg[/tex]

         q  is the charge on the electron with value  [tex]q = 1.60*10^{-19} \ C[/tex]

So

     [tex]V = \frac{(9.1 *10^{-31})}{2(1.60*10^{-19})} [(1.76*10^{5})^2 - (4.10*10^{6})^2][/tex]

     [tex]V = -47.65 N/C[/tex]

So given that the difference is negative then potential is higher at the origin