When a particle is a distance r from the origin, its potential energy function is given by the equation U(r)=kr, where k is a constant and \(r=x^2+y^2+z^2\)

(a) What are the SI units of k?

(b) Find a mathematical expression in terms of x, y, and z for the y component of the force on the particle.

(c) If U=3.00 J when the particle is 2.00 m from the origin, find the numerical value of the y component of the force on this particle when it is at the point (-1.00 m, 2.00 m, 3.00 m).