A single conservative force Fx= (6.0x-12) N, (x is in m), acts on a particle moving along the x axis. The potential energy associated with this force is assigned a value of 20J at x=0. What is the potential energy at x=3.0m?

Answer 1

Oh, how calculus explains it all..

the average force going the three meters is (6*3-12)-(6*0-12)/2
so the work put in to the object during pushing is
avgforce*distance=6*3/2 * 3=27 joules

so the PE at the end is 27+20J
check my math.