Kaplan 10th Edition DT Q31

Kaplan's Book

31) This problem asks us to solve for an estimation of the magnetic force acting on the electron.

Where orange represents the electron, black represents the electron's path, F[B] is the magnetic force, and v is the electron's velocity

In order for the electron to travel in a circular path, the magnetic force must point perpendicular to the velocity and toward the center of the path traveled. These are the same conditions for the net centripetal force. In this problem, the magnetic force is acting as the net centripetal force. So, we can use our equation for net centripetal force.

Where F[c] is the centripetal force, m is the mass, v is the velocity, and r is the radius

Next, we need to identify our given values.

Where m is mass, v is velocity, and r is radius.

Finally, we can plug in values and approximate the order of force.

Where F[c] is the centripetal force, m is the mass, v is the velocity, and r is the radius

Since we just want the best estimate of the power, we can select answer B, 10^(-17).

Answer: B