1. IB Physics 12
Mr. Jean
December 10th, 2013

2. The plan: Video clip of the day AC Motors IA investigate (6.3)
AC Motors
IA investigate (6.3)

3. AC Motors:

4. Sample Questions:
At the Equator near Earth’s surface, the magnetic field is approximately 50.0 μT northward and the electric field is about 100 N/C downward in fair weather.
Find the gravitational, electric, and magnetic forces on an electron with an instantaneous velocity of 6.00x106 m/s directed to the east in this environment.

5. Find the Gravitational Force

6. Find the electric force

7. Find the magnetic forces

8. Traveling Through a field:
A proton travels with a speed of 3.0x106 m/s at an angle of 37° with the direction of a magnetic field of 0.30 T in the +y direction.
What are (a) the magnitude of the magnetic force on the proton?
(b) the proton’s acceleration?

10. Example:
Sodium ions (Na+) move at m/s through a bloodstream in the arm of a person standing near a large magnet. The magnetic field has a strength of T and makes an angle of 51.0° with the motion of the sodium ions. The arm contains 100 cm3 of blood with 3.00x1020 Na+ ions per cubic centimeter. If no other ions were present in the arm, what would be the magnetic force on the arm?

14. Example:
A current I = 15 A is directed along the positive x axis and perpendicularly to a magnetic field. The conductor experiences a magnetic force per unit length of 0.12 N/m in the negative y direction. Calculate the magnitude and direction of the magnetic field in the region through which the current passes.

17. Example:
A single-turn square loop of wire, 2.00 cm on a side, carries a counterclockwise current of A. The loop is inside a solenoid, with the plane of the loop perpendicular to the magnetic field of the solenoid. The solenoid has 30 turns per centimeter and carries a counterclockwise current of 15.0 A.
Find the force on each side of the loop and the torque acting on it.