Answer:
Forces Due to Friction and Newton's Third Law
The forces on the cart include the forward force the horse exerts on the cart and the backward force due to friction at the ground, acting on the wheels. At rest, or at constant velocity, these two are equal in size, because the acceleration of the cart is zero.
You can use a spring scale, however, if you have all the information needed for the formula, it is best to use it as it offers a more precise answer.
<span>If only one force is acting an object it can have zero acceleration but it cannot have zero velocity. This occurs because acceleration is a change in speed, therefore when one force is acting upon the object the speed will remain constant. It can't have zero velocity because if one force is acting upon it then it is moving and no matter what that means it will have a velocity that isn't zero.</span>
A free body diagram is a diagram showing all of the forces acting on a system. It shows the relative magnitude and direction of each of the forces. Is that what you're looking for? I don't fully understand what you're asking
The total electric potential energy is
.
Electric Potential Energy of a System of Charges :
The system's electric potential energy is equal to the amount of work necessary to create a system of charges by guiding them toward their designated locations from infinity against the electrostatic force without accelerating them. The symbol for it is U.U=W=qV. Electrostatic fields are conservative, therefore the work is independent of the path.
Assume three charges q₁ , q₂ and q₃ bring from infinity to point P.
To bring q₁ no work is done,
where, V = electric potential energy.
q = point charge.
r = distance between any point around the charge to the point charge.
k = Coulomb constant; k = 9.0 × 109 N.
Now bring q₂,

Work done by q₁ ;

Now bring q₃,

Work done on q₃ by q₁ and q₂
![W= q_{3} [ V_{1} + V_{2} ]](https://tex.z-dn.net/?f=W%3D%20q_%7B3%7D%20%5B%20V_%7B1%7D%20%2B%20V_%7B2%7D%20%5D)


This work done is stored in the form of potential energy.
∴U=W= potential energy of three systems.
Learn more about electric potential energy here:
brainly.com/question/15801030
#SPJ1