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03. A proton is placed at point A between the two oppositely-charged parallel pl

ID: 1792765 • Letter: 0

Question

03. A proton is placed at point A between the two oppositely-charged parallel plates Problem 03 shown in the diagram to the right. The potential difference between the plates is 3000 V and the plates are 16.0 cm apart. a.) What is the electrostatic force (magnitude) acting on this charge at point A? b.) What is the potential difference between points A and B? c.) If the charge is released from A and allowed to accelerate to point B, what will be its velocity when it reaches point B? d.) What is the minimum work done in moving the charge from point A to C?

Explanation / Answer

q=+1.6*10^-19 C, V=3000V, d=0.16m

a)

V=E*d

E=V/d =3000/0.16 = 18750 V/m

F=qE = (1.6*10^-19)*(18750) = 3.0*10^-15 N

b)

V= E*x = (18750)(0.09) = 1687.5 V

c)

Use work-Energy theorem,

W=qV

1/2mv^2 = qV

v=sqrt[2qV/m]

v=sqrt[(2*1.6*10^-19*1687.5)/(1.67*10^-27)] = 5.7*10^5 m/s

d)

WA to B = q*V= (1.6*10^-19)*(1687.5) = 2.7*10^-16 J

WB to C = q*V= (1.6*10^-19)*(0) = 0 J

WA to C = WA to B + WB to C = 2.7*10^-16 J + 0 J = 2.7*10^-16 J