C Secure httpssession masteringphysicscommyctitemviewassig U
Solution
Data:
 Initial speed, Vi = 4.8 x 106 m/s
 Charge of the proton, q = 1.6 x 10-19 C
 Mass of the proton, m = 1.67 x 10-27 kg
 Solution:
 PART (a)
 Distance, s = 0.034 m
 Final speed, Vf = 0 m/s
 Acceleration, a = F / m
 = q E / m
 = (1.6 x 10-19)E / (1.67 x 10-27)
 = 9.58 x 107 E
 From the equations of motion,
 Vf2 - Vi2 = 2as
 0 - (4.8 x 106 )2 = 2(9.58 x 107 E )(0.034)
 So, E = - 3.537 x 106 N/C
 Magnitude of electric field E = 3.537 x 106 N/C
 Direction: Horizontally towards left
 PART (b)
 The angle counterclockwise from left is zero.
 PART (c)
 Acceleration, a = q E / m
 = (1.6 x 10-19)(-3.537 x 106) / (1.67 x 10-27)
 = - 3.388 x 1014 m/s2
 From the equation of motion,
 Vf = Vi + at
 0 = 4.8 x 106 + ( - 3.388 x 1014 ) * t
 Time, t = 1.42 x 10-8 s
 
 PART (d)
 Mass of electron, m = 9.1 x 10-31 kg
 Charge of electron, q = 1.6 x 10-19 C
 Distance, s = 0.034 m
 Final speed, Vf = 0 m/s
 Acceleration, a = F / m
 = q E / m
 = (1.6 x 10-19) E / (9.1 x 10-31)
 = (1.76 x 1011) E
 From the equations of motion,
 Vf2 - Vi2 = 2as
 0 - (4.8 x 106)2 = 2 (1.76 x 1011 E)(0.034)
 So, E = - 1925.13 N/C
 Magnitude of electric field = 1925.13 N/C
 Direction: Horizontally towards the right


