# Physics Problem: A bar of length l = 15.0 cm and mass m = 0.180 kg, having a resistance of R = 150 , is free to slide on two vertical,...

A bar of length l = 15.0 cm and mass m = 0.180 kg, having a resistance of
R = 150 , is free to slide on two vertical, conducting rods, as shown.
There is a uniform magnetic field of magnitude B = 1.08 T directed out of the
paper in the yellow-shaded region. An emf of E = 3,000 V is placed across the bar.
The bar is then pushed down a distance d = 7.50 cm into the region with the
magnetic field, as shown in Fig.-3b.
a) What is the highest height the bar will reach after it is let go? (Ignore the emf
that is generated by the motion of the bar in the magnetic field.)
b) After the bar is let go, what is the emf generated by the motion of the bar just
before it reaches y = 0?
c) If the bar ever gets above y = 0, what would the generated emf be in the region
above y = 0?
d) Discuss as completely as you can, how the generated emf will affect the motion
of the bar.
e) Will the effect of the generated emf on the motion of the bar be greater or less if
the bar is pushed down more than 7.50 cm before it is let go?
asked 7 years ago in Physics