Figure gives the potential energy U of a magnetic dipole in an external magnetic field B, as a function of angle Φ between the directions of B and the dipole moment. The vertical axis scale is set by U? s = 2.0 x 10-4 J. The dipole can be rotated about an axle with negligible friction so as to change Φ. Counterclockwise rotation from Φ = 0 yields positive values of Φ, and clockwise rotations yield negative values. The dipole is to be released at angle Φ = 0 with a rotational kinetic energy of 6.7 x 10-4 J, so that it rotates counterclockwise. To what maximum value of Φ will it rotate? (In the language of Section 8-6, what value d is the turning point in the potential well of Figure)?

Transcribed Image Text:

(10 J) U(10- 180° -180°