
#1
Mar807, 08:16 AM

P: 483

1. The problem statement, all variables and given/known data
Positive point charges q_1= 6.90 microC and q_2= 2.90 microC are moving relative to an observer at point P as shown in the figure. The distance from the observer to either charge is originally d = 0.190 m.The two charges are at the locations shown in the figure. Charge q_1 is moving at a speed of v_1 = 3.20×10^6 m/s and q_2 is moving at a speed of v_2 = 9.40×10^6 m/s. a. What is the magnitude of the net magnetic field they produce at point P ? b. What is the direction of the net magnetic field they produce at point P ? 2. Relevant equations See below. 3. The attempt at a solution I think I mixed up my signs for the cross product of v and r. Are the two fields in opposite directions? Any advice on those parts are appreciated. B_1 = (mu_0/4*pi)*[(q*v vector*r vector)/(r^3)] v vector = 3.20*10^6 m/s*i r vector = (0.190 m)*j v vector*r vector = (3.20*10^6 m/s)i*(0.190 m)j = 60800 m^2/s*k B_1 = [(1*10^7 T*m/A)*(6.90*10^6 C)(60800 m^2/s*k)]/[0.190 m]^3 = (6.12*10^5 T)*k ?? B_2 = (mu_0/4*pi)*[(q*v vector*r vector)/(r^3)] v vector = 9.40*10^6 m/s*i r = 0.190 m*j v vector*r vector = (9.40*10^6 m/s*i)*(0.190m*j) = 1786000 m^2/s B_2 = [(1*10^7 T*m/A)*(2.90*10^6 C)(1786000 m^2/s*k)]/[0.190 m]^3 = (7.55*0^5 T)*k ?? B_total = (6.12*10^5 T)*k  (7.55*0^5 T)*k = (1.37*10^4 T)*k out of the page?? (negative zaxis?) Thanks. 



#2
Mar807, 06:50 PM

P: 483

Can anyone please check over my workings, particularly my signs?
Thank you very much. 


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