Rail Gun Constants Part A A rail gun uses electromagnetic forces to accelerate a
ID: 1660291 • Letter: R
Question
Rail Gun Constants Part A A rail gun uses electromagnetic forces to accelerate a projectile to very high velocities. The basic mechanism of acceleration is relatively simple and can be illustrated in the following example. A metal rod of mass 10.0 g and electrical resistance 0.400 rests on parallel horizontal rails that have negligible electric resistance. The rails are a distance L 7.00 cm apart. (Figure 1)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= 5.60x10-2T. 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 Find , the coefficient of static friction between the rod and the rails Give your answer numerically View Available Hint(s) Submit Provide Feedback Figure 1 of 1>Explanation / Answer
the idea here basically is that a current carrying conductor experiences force due to a magnetic field
with magnitude :
F = i *(l cross B)
current in the rod = voltge/resistance = 5/0.4 = 12.5
force when B = 5.6 * 10^-2
F = 12.5 * 5.6 * 10^-2 *7 *10^-2 = 0.049
UNTIL THIS MOMENT THIS FOREC WAS BALANCED BY THE STATIC FRICTION
so max static friction = force exerted by the magnetic field
0.049 = u Mg u = coeff of static friction
0.049 = u *10*10^-3 *9.8
u = 0.5
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.