Class Management I Help HW2: Electric Field and Matter Begin Date: 1/30/2018 12:
ID: 1869924 • Letter: C
Question
Class Management I Help HW2: Electric Field and Matter Begin Date: 1/30/2018 12:00:00 AM - Due Date: 2/7/2018 11:59:00 PM End Date: 5/9/2018 11:59:00 AM (1496) Problem 7: A basic mass spectrometer can be constructed by shooting a charged particle through a pair of charged plates and measuring the deflection angle at the end of the plates. This device can measure the ratio of the charge to the mass of the particle. Such a device is shown in the figure, which has a length L, a plate separation h, and a constant electric field E between the plates as shown. In this problem, you may assume the particle deflection is small relative to the separation h of the plates ©theexpertta.com h/2 h/2 50% Part (a) Find the tangent ofthe angle shown in the figure, in terms of the variable which describe the spectrometer as well as the the mass m, charge q, and initial speed v of the particle. You may ignore the force of gravity on the particle 50% Part (b) For a particular mass spectrometer with parameters L = 1.5 m. E-21 Nc, v = 6.6x104 m/s, the measured angle is = 0.55 rad. Calculate the charge to mass ratio (R = q/m), in C/kg, of the outgoing particles. Grade Summa Deductions Potential 096 100% 7 8 9 sin0 cotanasin acos0 atanO acotan sinhO cosh tanh cotanh0 cosO tan Submissions Attempts remaining: 5 (306 per attempt) detailed view END Degrees Radians EL CLEAR Submit Hint I give up! Hints: 0% deduction per hint. Hints remaining: 3 Feedback: 0% deduction per feedback.Explanation / Answer
part(a)
along vertical
displacement y = L
acceleration ay = 0
speed vy = v
y = vy*t + (1/2)ay*t^2
L = v*t
t = L/v
along horizontal
acceleration ax = F/m = Eq/m
time t = L/v
initial speed v0x = 0
final speed vx = vox + ax*t
vx = E*q*t/m = EqL/(vm)
tantheta = vy/vx
tantheta = EqL/(v^2*m)
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charge to mass ration R = q/m = v^2*tantheta/(EL)
R = ((6.6*10^4)^2*tan0.65)/(21*1.5)
R = 1.05*10^8 C/kg