Find μsμsmu_s, the coefficient of static friction between the rod and the rails. Express the coefficient of static friction in terms of variables given in the introduction.

The question is incomplete. However the complete question is :

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 m and electrical resistance R rests on parallel horizontal rails (that have negligible electric resistance), which are a distance L apart. The rails are also connected to a voltage source V, so a current loop is formed.

The vertical magnetic field, initially zero, is slowly increased. When the field strength reaches the value , the rod, which was initially at rest, begins to move. Assume that the rod has a slightly flattened bottom so that it slides instead of rolling. Use g for the magnitude of the acceleration due to gravity.

Find μs, the coefficient of static friction between the rod and the rails.

Express the coefficient of static friction in terms of variables given in the introduction.

So the answer is :

Explanation:

It is given : B =

Therefore, using force on the current carrying wire is:

Therefore,

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it

the right answer is 0.3 meters per second