In physics, potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, its electric charge, or other factors.Common types of potential energy include the gravitational potential energy of an object that depends on its mass and its distance from the center of mass of another object, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field. The unit for energy in the International System of Units (SI) is the joule, which has the symbol J.
The term potential energy was introduced by the 19th-century Scottish engineer and physicist William Rankine, although it has links to Greek philosopher Aristotle's concept of potentiality. Potential energy is associated with forces that act on a body in a way that the total work done by these forces on the body depends only on the initial and final positions of the body in space. These forces, that are called conservative forces, can be represented at every point in space by vectors expressed as gradients of a certain scalar function called potential.
Since the work of potential forces acting on a body that moves from a start to an end position is determined only by these two positions, and does not depend on the trajectory of the body, there is a function known as potential that can be evaluated at the two positions to determine this work.
Hi, can someone please help me on this problem. I'm not sure what to do with the equation given. I tried taking the derivative, partial, and anti and nothing seems to be working. Can someone please give me a hint on how to start this problem.
Thanks in advance.
Suppose the following...
Is there a quick way to figure out the total potential energy between more than 2 charges without having to find the potential at each point and the. Multiplying it by the charge at that point and adding it all up?
For example - a 2D square with a charges Q, 2Q, -3Q, and another Q at each...
**sorry, the title should probably read determining a point at higher potential and potential energy
So I feel like this is a really simple example, but I have a test tomorrow and this potential and potential energy stuff is really starting to not make sense...
I know that a charge going in the...
I have a pressure vessel of volume V= 1 m^3 . The atmospheric pressure Patm = 101 kPa and Tatm = 22 C. I slowly pump liquid water into the pressure vessel until the internal pressure reaches P1 = 15 MPa. Also, the process is isothermal because the water was pumped in slowly and heat is exchange...
When the dipole makes an angle with an electric field, its potential energy is given as the work done in bringing the dipole from the position, when it is aligned with the electric field direction, to a desired position, i.e
W = pE [-cosθf -(-cosθi)] ...eq(1)
p = moment of the dipole...
The picture shows the potential due to ring charge.
Please show the full steps of deriving the equation of electrical potential. I don't know how to start at all.
NOTE:
The electric potential of the revolving symmetrical ring electric charge related to the axis z as depicted in the diagram...
we have an inversed pendulum(ignore the car)
and we choose the coordinate system to be upwards
the potential energy PE=mgz (z will be hegative since( O,k) is upwards right?) z is always under O.
but in the textbook they basically take the absolute value of h i don't understand why?
Homework Statement
A 3-kg mass is attached to a light string of length 1.5 m to form a pendulum. The mass is given a initial speed of 4 m/s at its lowest position. When the string makes and angle of 30° with the vertical, find (a) the change in potential energy of the mass, and (B) the speed...
Homework Statement
A sled and its rider have a mass of 90 kg and a speed of 3 m/s at point A on the frictionless hill of Figure 5.25. At the bottom of the hill, the sled moves onto a rough surface with a coefficient of friction of .6. How far from the base of the hill will the sled move...
A mass m = 6.2 kg hangs on the end of a massless rope L = 1.96 m long. The pendulum is held horizontal and released from rest.
1) How fast is the mass moving at the bottom of its path?
I calculated this to be 6.201 m/s using the equation v=√(2gh) (correct)
2) What is the magnitude of the...
Electric potential energy of a charge q at a point in an electric field due to any charge configuration as the work done by the external force in bringing the charge q from infinity to that point without any acceleration..
In this definition, why charge is moved without any acceleration?
Homework Statement
A simple pendulum is constructed by supporting a .375 kg steel sphere by a thin string 1.2 in length and of negligible mass. The pendulum is released form rest at a position where the string makes an angle of 35° with the vertical. What is the speed of the sphere as it...
If a positive charge A moves towards another stationary positive charge B then the A's electric potential energy increases. But shouldn't the electric potential energy of B also increase as it is also in a way moving towards the A inside the A's electric field?
So shouldn't the total...
I got a quick question regarding the potential energy of a fluid (see picture). If I want to express the potential energy of a fluid (with a given volume) above the reference line x, using nothing but the given variables/constants, would this be the correct way to do so?
picture
Homework Statement
A molecular bond can be modeled as a spring between two atoms that vibrate with simple harmonic motion. Figure P14.63 shows an SHM approximation for the potential energy of an HCl molecule. For E < 4 * 10^-19 J it is a good approximation to the more accurate HCl...
In a velocity selector apparatus, i had an electric potential set across two points, and a proton at rest at one end. The potential was 350 V.
My instructor used :
qV = 1/2 mv^2 to find the velocity at the end of the apparatus.
Where did the left hand side of the eqn come from??
Is it that ideal gases do not possesses potential energy because there are no intermolecular forces. But, real gases do have potential energy and its potential energy is the highest among the different phases. ( Potential Energy of Gas>Liquid>Solid ). I need someone to make these things clear to...
A conservative force of 5 N causes a body to move 2 m in the direction of the force. The change of the body’s potential energy associated with the force is:
(a) zero,
(b) +10 J,
(c) -10 J, (d) infinite.
Let's say the force is pushing the body for 2m, there must be a change in KE. But, for...
And when they are negative. I have grasped most of my textbook but this seemingly easy concept keeps going over my head. I'm in e and m right now but still can't understand why it is Vba= - integral a to b E times dl.
When a positive charge leaves the positive part if the battery it has maximum electric potential energy then as it moves through a wire with a zero resistance the charge is closer to the negative side of the battery.
So, while traveling in a wire in a circuit does it lose electric potential...
Hi everyone , I'm really stuck with an exercise I can't solve any question and it is really important ! I need help :
Two identical billiard balls start at the same height and at the same time and roll along different tracks,as shown in figure attached
1- Which ball has the highest speed...
Homework Statement
How much work is done by the spring on the object as it stretches 0.02m? The spring has a k value of 270N/m and the object is 0.55 kg.
Homework Equations
Ui = Uf - Ws
Ws = 0.5kxf2 - 0.5kxi2
The Attempt at a Solution
Assuming Ui is when the spring isn't...
Homework Statement
A cone of circular cross section having base radius R, mass M and height L is suspended from its base as shown in figure. The material of cone has Young's modulus Y. If the elastic potential energy stored in the cone can be expressed as:
$$E=\frac{m^ag^bL^c}{d\pi^eY^fR^g}$$...
Homework Statement
I'll provide a picture for a clearer view: http://i.imgur.com/wkXPcJn.jpg
Suppose that the slender rod starts at rest at theta = 0. For convenience we chose the datum at theta = 0.
Now I want to calculate the gravitational potential energy at a later instant when theta =...
If a particle is moving with kinetic energy T(x) in a potential field of energy V(x), why is the total energy E(x) = T(x) - V(x), i.e. why is potential energy negative?
The way I have seen it explained is that the potential energy is less than if the particle was an infinite distance from the...
1. Explain why the electron moves in the above way (from left to right between two parallel plates that is positively charged on the left, negatively charged on the right) in terms of electric potential energy
Homework Equations
3. I know the electron moves from left to right when...
So I've always been confused about this. Suppose you have your normal pendulum: length L, mass m, and angle Θ.
When you describe the potential energy PE = mgh, you must decide where to measure your h from. Throughout my years I've seen it measured from the mass to the 0 equilbrium point where...
Homework Statement
A 5kg ball (m), is to be dropped 1 meter (h) in a vacuum with no resistance in the Earth's gravity (g).
Use the speed and motion equations to show that its KE at impact is equivalent to its PE at its starting point.
Homework Equations
PE = mgh
KE= 1/2mv^2...
Homework Statement
A mass moves along the x-axis with potential energy
U(x)= - U0 a^2 / (a^2 + x^2). What is the angular frequency assuming the oscillation is small enough to be harmonic?
Homework Equations
w^2 = k/m with w as the angular frequency
F= -kx = -(gradient) U...
Homework Statement
A compressed spring has 138 J of energy stored in it. When it is decompressed by 125 cm, it now stores 82.6 J of energy. What is the spring constant
Homework Equations
General:
ΔU = 1/2kxf2 - 1/2kxi2
U(x) = 1/2kx2
U1 = 1/2kx12
U2 = 1/2k(x1 + 1.25 m)2
The...
Homework Statement
A 20 kg child slides down a slide at a playground. The slide is 5 meters long, and is inclined at an angle of 37 degrees above the horizontal. What is the child's change in potential?
Homework Equations
PE=mgy
With m=mass, g=gravity, and y=distance.
The Attempt...
Can we say that positive potential energy means energy is given out by the system when it is brought to the present state of configuration and negative potential energy implies that energy needs to be provided to the system to achieve the present state?
Gravitational Potential energy is the work done against the gravity to move a mass from one point to the other.
So if a mass was falling down to the earth, how is the potential energy defined?
Why is gravitational potential energy defined at infinity?
Like here on Earth there is Zero potential energy at the center of the Earth (if you could theoroeetically go there) so why not define it as 0 at zero distance from the force supplier instead of at infinity? I understand why the...
When a rocket is launched into space, its GPE increases and its KE decreases.
If we equate the change in both energies we can find out the velocity of the rocket at a certain height.
Δ GPE = Δ KE
Does the equation already take the opposing gravitational force of Earth into account?
Assume Earth's radius R and there is a mass m. We put that mass in height of R from the Earth's surface. I want to calculate it's potential energy.
I calculated it and got mgR/4 but my teacher said the answer is mgR/2 . Why my answer is wrong?
I just calculated the gravity in the height of R...
Conservative Forces and Potential Energy
Homework Statement
A mass hangs on the end of a massless rope. The pendulum is held horizontal and released from rest. When the mass reaches the bottom of its path it is moving at a speed v = 2.1 m/s and the tension in the rope is T = 19.3 N.
1)...
For a mass on a spring (vertical set up) why is potential energy U defined as 1/2 kx^2? This is just the elastic potential energy. Shouldn't it be U = 1/2 kx^2 + mgh? Both the elastic AND potential energy? Also, for a simple pendulum at a very low amplitude, the potential energy is all...
Homework Statement
Three masses are disposed in a circular lane and linked with springs (resting lengths Lo). Find the potential energy and, from it, the equilibrium positions. (see image: https://www.dropbox.com/s/evqcspwlj68p5n9/2014-02-05%2016.07.07.jpg )
Homework Equations
The...
There is several things I am confused about with gravitational potential energy. So, first of all, shouldn't U=mgh always be written ΔU=mgΔh, because isn't that equation only dealing with differences of potential energies when close to the surface of earth?
Second, with the equation U=-GMm/r...
Homework Statement
A point charge q2 = -4.5 μC is fixed at the origin of a co-ordinate system as shown. Another point charge q1 = 3.6 μC is is initially located at point P, a distance d1 = 7.3 cm from the origin along the x-axis
2) The charge q2 is now replaced by two charges q3 and q4...
Homework Statement
The electric field in a particular region of space is found to be uniform, with a magnitude of 700 N/C and parallel to the +y direction.
(a) What is the change in electric potential energy of a charge [q = 6.5 mu or micro CC if it is moved from [(x, y) = (20 cm, 45 cm)]...
Homework Statement
A particle is connected to a spring at rest. Because of weight, the mass moves a distance \Delta x. Calculate the value of the elastic constant k
Homework Equations
U_{PE} = \frac{1}{2}k\Delta x^2
U = mgh
F = ma (in general)
F = kx (Hooke's Law)
The Attempt at a...
Homework Statement
Find the derivative of \frac{Q}{4\pi \epsilon_0 r}
Homework Equations
\frac{d}{dx} \frac{1}{x}=\ln x
The Attempt at a Solution
Assuming Q and the rest of the variables under it are constant, \frac{Q}{4\pi \epsilon_0}\frac{1}{r} then the derivative should be \ln...