What is the rate at which a force acts? what is the word for it?

Question

Ok, i'm trying to describe how a pulley holding 2 masses of unequal mass.

Say 5.7 kg and 5.5 kg and earth's gravity is the only force (well the tension in the ropes, we can say is massless rope with no friction).

Ok, the acceleration of the two objects depends on "how much bigger than m1 is than m2" which I call a "net mass" (sorry for using finance background terminology).

Now that "net mass" times "g" = the contribution to powering that which you'll observe if you "let go" and let them start moving.

The force of the .2*9.8 = 1.96 newtons

This 1.96 newtons is Force

The force is applied constantly.

1.96 Newtons per second is the amount of "oomph!" to get the thing moving.

Oh wait, could I say that it is the "potential energy"

(m2-m1)g = the potential energy?

I want to write notes that I'll understand 20 years from now. The inertia is m1+m2

What is the "difference of masses" times "g"

What can I call this, and makes GREAT INTUITION for recall when i'm a senior citizen?

Answer 1

The masses held in position have as you say a potential energy - measured in joules.

The tension in the rope holding them is not actually doing any work as such as work is force x distance (1Nm = 1 J).

However if a person were to be holding that rope they would be expending energy to resist that force, in joules per second .

So the potential energy is being resisted for a certain time - this is the power that the person needs in joules per second or watts to prevent the masses from falling.