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=x2+y2+z2√

(a) what are the si units of k?

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

part c (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).