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Rail Gun Part A A rail gun uses projectile to very high velocities. The basic me

ID: 1790968 • Letter: R

Question

Rail Gun Part A A rail gun uses projectile to very high velocities. The basic mechanism of netic forces to accelerate a Find A, the coefficient of static friction between the rod and the rails. Give your answer numerically. is relatively simple and can be illustrated in the following example. A metal rod of mass 30.0 g and electrical resistance 0.200 2rests on parallel horizontal rails that have negligible electric a distance L 9.00 crn apart. (Figure!) The rails are also connected to a voltage source providing a voltage of V=5.00 V The rod is placed in a vertical magnetic field. The rod begins to slide when the field reaches the value B 6.53x10-2 T. Assume that the rod has a slightly flattened bottom so that it slides instead of rolling. Use 9.80 m/s2 for the magnitude of the acceleration due to gravity Hints resistance. The rails are My Answers Give Up Provide Foedback Continue

Explanation / Answer

Current carrying conductor experiences a magnetic force in horizontal direction as B is in z-direction and current flow is

in y-direction. Conductor slides when B becomes 6.53 x 10^-2 T. This should be equal to frictional force.

usmg = BIL

us = BIL / mg

us = B*(V/R)*L / mg

where,

B = 6.53 x 10^-2 T

V = 5 V

R = 0.200 ohm

L = 0.09 m

m = 30 g = 30 x 10^-3 kg

us = [ 6.53 x 10^-2 x (5/0.200) x 0.09 ] / (30 x 10^-3 x 9.81)

us = 0.146925 / 0.2943

us = 0.499 = 0.5 (approx)