Apotential energy function is given by u(x)=(3.00j)x+(1.00j/m2)x3. what is the force function f(x) (in newtons) that is associated with this potential energy function?

Given potential energy as a function of time is

now for all conservative forces we know that

now we will differentiate the potential energy with respect to x

so now we will have

now we will have

so the force associated with the given potential energy is given as

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27