(a) How far will the electron travel in thefield before stopping momentarily? m

Question

(a) How far will the electron travel in thefield before stopping momentarily?
                              m
(b) How much time will have elapsed?
s
(c) If, instead, the region of electric field is only 3.00 mm long (too small for the electron to stop),what percentage of the electron's initial kinetic energy will belost in that region?
%

I tried to do kinematics with this to get deltax as well as the acceleration to no avail. I don't know if I just keep doing calculations wrong or what but your help would be greatly appreciated!!

Explanation / Answer

a) q E = m a

a = q E/m

v^2 = v0^2 + 2 a x

0 = 8.5E6^2 -2*(1.6E-19*1000/9.11E-31)*x

x=0.206 m

b)v = v0 + at

0 = 8.5E6 -(1.6E-19*1000/9.11E-31)*t

t=4.84E-8 s

c) so dV = Edx = 1000*3.0E-3 = 3 V

q dV/KE = 1.6E-19*3/(0.5*9.11E-31*8.5E6^2)=0.0146 = 1.46%

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.