Magnetic and Coulomb forces between moving charges and field from wire with external field

[metz143]

Hello. Our instructor gave us 2 sets of problems. Deadline is on monday. If anyone can share his / her idea, I would really appreciate it.

Here are the problems:
1. Two positive point charges q and q2 are moving relative to an observer at point P; P measures the forces on the charges.

a) What is the direction of the force that q2 exerts on q?
b) what is the direction of the force that q exerts on q2?
c) if V=V2= 3.00 x 10^6 m/s. What is the ratio of the magnitude
of the magnetic force that acts on each charge to that of the coulomb
force that acts on each charge?


2. A long straight wire lies along the y-axis and carries a current of 5.00A in the y-direction. In addition to the magnitude Bo with magnitude 1.75x10^-6 T is the +x direction. What is the total field(magnitude and direction) at the following points to the xz plane:
a) x=0 ; z=2.00m
b) x=2.00 m; z=0
c) x=0;z=0.50m

Any help would be very much appreciated.Thank you in advance.

 

[member 553083]

For the first problem:a) The force that q2 exerts on q will be directed from q2 towards q. b) The force that q exerts on q2 will be directed from q towards q2. c) The ratio of the magnitude of the magnetic force to that of the Coulomb force is equal to (V*q2)/(4πε0q), where V is the velocity of the charges, q2 is the charge of q2, q is the charge of q, and ε0 is the permittivity of free space. For the second problem:a) At the point x=0, z=2.00m, the total field will have a magnitude of 0.00792 T and will be in the +x direction. b) At the point x=2.00m, z=0, the total field will have a magnitude of 0.00592 T and will be in the +x direction. c) At the point x=0, z=0.50m, the total field will have a magnitude of 0.0317 T and will be in the +x direction.

 

[thepatientmental]

Hello,

I'm not sure if I can give you a complete solution, but I can definitely give you some ideas on how to approach these problems.

For problem 1, you can use Coulomb's Law to determine the direction of the force between the two charges. Remember that like charges repel each other, so the force will be in the direction away from q2 towards q. Similarly, the force exerted by q on q2 will be in the opposite direction.

For part c, you can use the formula for magnetic force (F = qvBsinθ) and Coulomb's Law (F = kq1q2/r^2) to find the ratio between the two forces. Remember that the magnetic force depends on the velocity of the charges and the strength of the magnetic field, while the Coulomb force depends on the distance between the charges and the strength of the charges.

For problem 2, you can use the right-hand rule to determine the direction of the magnetic field created by the wire. Then, you can use the formula for the magnetic field of a long straight wire (B = μ0I/2πr) to find the magnitude of the field at each point. Remember to consider the direction of the current and the distance from the wire to determine the direction of the field.

I hope this helps and good luck with your problems! Remember to show your work and double check your calculations. If you're still stuck, don't be afraid to ask your instructor or classmates for help. Collaboration can often lead to a better understanding of the material. Best of luck!