A proton (mass=1.67x10^-27 kg, charge= 1.60x10^-19 C) moves from point A to point under the influence of an electrostatic force only. At point A the proton moves with a speed of 50 m/s. At point B the speed of the proton is 80 km/s. Determine the potential difference VB-VA in volts.

Respuesta :

Answer:

[tex]VB -  VA  =  - 33.4[/tex]

Explanation:

Generally the workdone in moving the proton is mathematically represented as

     [tex]W  =  KE_f  - KE_i[/tex]

Where [tex]KE_i \ and \  KE_f \  are\  the\  initial  \  and  \  final \  kinetic \  energy  [/tex]

So

    [tex]KE_i  =  \frac{1}{2} m v_a^2[/tex]

Here [tex]v_a[/tex] is the velocity at A with value  50 m/s

So

    [tex]KE_i  =  \frac{1}{2} (1.67*10^{-27}) * 50^2 [/tex]

    [tex]KE_i  = 2.09 *10^{-24} \  J  [/tex]

Also  

     [tex]KE_f  =  \frac{1}{2} m v_b^2[/tex]

Here [tex]v_a[/tex] is the velocity at A with value [tex]80 km/s = 80000 m/s [/tex]

=>   [tex]KE_f  =  \frac{1}{2} (1.67*10^{-27}) * 80000^2 [/tex]

=>   [tex]KE_f  = 5.34 *10^{-18} \  J[/tex]

 So

    [tex]W  =   5.34 *10^{-18}  - 2.09 *10^{-24}[/tex]

     [tex]W  =   5.34 *10^{-18}  m/s[/tex]

Now this workdone is also mathematically represented as

     [tex]W =  q *  V[/tex]

So  

    [tex]   q *  V =   5.34 *10^{-18}   [/tex]

Here  [tex]q =  1.60*10^{-19} C[/tex]

So

        [tex]   V =   \frac{5.34 *10^{-18} }{1.60*10^{-19}}[/tex]

         [tex]   V =   33.4 \  V  [/tex]

Generally proton movement is in the direction of the electric field it means that  [tex] VA>VB [/tex]

So

    [tex]VB -  VA  =  - 33.4[/tex]