4. A particle of mass m slides without friction along a wire bent into the shape of a circular helix whose equation is z=a0, r=R, where r, 0, and z are the usual cylindrical coordinates, and a is a constant. The particle is attracted to the origin with a force equal to k times the distance from the origin. Write and solve the equation of motion, using the constrains to reduce the problem to one involving a single variable.

4. A particle of mass m slides without friction along a wire bent into the shape of a circular helix whose equation is z=a0, r=R, where r, 0, and z are the usual cylindrical coordinates, and a is a constant. The particle is attracted to the origin with a force equal to k times the distance from the origin. Write and solve the equation of motion, using the constrains to reduce the problem to one involving a single variable.