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scholio
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Homework Statement
a wire 0.3 meters in length is suspended in a region in which a uniform magnetic field of 4Teslas points into the page as shown ( see attach.). the wire is dropped at time t = 0 seconds. at what times will there be an electric potential of 98 volts between the ends of the wire? also, which end of the wire will have the higher potential?
Homework Equations
position x = 1/2(at^2) where a is acceleration due to gravity = 9.8m/s/s, t is time
force of gravity F = mg where m is mass, g is gravity = 9.8m/s/s
1/2(mv^2) = qV where q is charge, V is electric potential
magnetic force F_m = qv X B where q is charge, v is velocity, B is magnetic field, X indicates cross product
gravitational potential energy U = mgh where m is mass, g is gravity = 9.8 m/s/s, h is height = x
gravitational potential energy = kinetic energy = 1/2 (CV^2) = 1/2(mv^2) where C is capacitance, V is electric potential, m is mass, v is velocity
The Attempt at a Solution
i'm guessing most of the above equations are not needed at all.
i'm not too sure how to do this, but this is what I've been scheming: use the " 1/2(mv^2) = qV " to solve for v while holding m and q constant.
sub in v into magnetic force eq and solve for force, and since force F = ma = m ( 1/2(at^2)) where m is constant, and a = 9.8m/s/s i can solve for t.
is this close? i haven't included the given length of 0.3 meters, though.
as for the second 'part', determining which end of the wire has the higher potential i am not too sure about, tips appreciated.