Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The lower end of the thin uniform rod in (Figure 1) is attached to the floor by

ID: 1555424 • Letter: T

Question

The lower end of the thin uniform rod in (Figure 1) is attached to the floor by a frictionless hinge at point P. The rod has mass 0.0920 kg and length 23.0 cmand is in a uniform magnetic field 0.130 T that is directed into the page. The rod is held at an angle 55.0 above the horizontal by a horizontal string that connects the top of the rod to the wall. The rod carries a current 12.0 A in the direction toward P.

Calculate the tension in the string. Use the fact that =12IBL2 for a uniform bar of length L carring a current I in a magnetic field B.

Express your answer with the appropriate units.

X X X X

Explanation / Answer

Tm = 1/2 I B L2

Torque due to gravity Tg = m g * L/2 * cos theta

Torque due to tensio = T L sin theta

Balancing torque's T = IBL + m g cos theta / 2 sin theta

T = ((12 * 0.130 * 23 * 10-2) + (0.092 * 9.8 * cos 55)) / ( 2 * sin 55)

T = 0.535 N