Can an object have negative kinetic energy?

Answer 1

The kinetic energy of an object can never be negative. Why? The equation for kinetic energy is 1/2mv^2. Mass cannot be negative, as it is mass. Though velocity can be negative, it will never result in a negative resultant because it will be squared. An example would be -4 squared. -4 squared will result in a positive 16. Even -4000 squared will still be a positive 16000000. So in conclusion, kinetic energy will never be negative.

Answer 2

Kinetic energy is a scalar quantity. So, irrespective of the direction, only the magnitude of the energy is considered. Even if the velocity of the body is negative with respect to the considered frame of reference, as the square of the velocity is taken while finding the kinetic energy, kinetic energy can never be negative. We can also say that no form of energy can be negative.

Kinetic energy can never be negative because in its equation, KE = ½mv², v is speed which is a scalar quantity. It is incorrect to say that no form of energy can be negative. For example, gravitational potential energy can be negative because in its equation, PEg = mgh, h is height which can sometimes be positive or negative depending on the situation.

Negative Kinetic energy is found in Quantum mechanics , negative kinetic energy values come from solutions from the Schrodinger equation dealing with quantum tunneling. the region where the tunneling takes place show imaginary momentum, imaginary wave number and negative kinetic energy.

Answer 3

Electric potential energy absolutely can be negative. Before I attempt to explain it, make sure to recognize that electric potential and electric potential energy are two different but very closely related concepts. Electric potential (measured in Volts or Joules per Coulomb) is a measure of the potential energy of of a test charge of q=1C in an electric field (produced by a point charge, point charge distribution, or continuous charge distribution). Electric potential at a point distance r from a source point charge (charge=Q) is simply: V=kQ/r. Notice V at the point will be positive for a source point charge of positive polarity and negative for a source point charge of negative polarity.

Electric potential energy and electric potential are measured over a distance d as they are the measure of the difference of electric potential or electric potential energies in space from point a in an electric field to point b in an electric field. Usually you will see the equation for electric potential energy of a movable charge written as (Ub-Ua=q(Vb-Va)) where Ub and Vb are the electric potential energy and electric potential respectively at point b, Ua and Va are the electric potential energy and electric potential respectively at point a, and q is the charge of the movable charge .

We can easily set point a to lay at infinity, and the U and V at infinity are zero. This reduces the above equation for electric potential energy of a movable charge to U=qV. With that equation in mind, we can see two situations when the electric potential energy could be negative: either the polarity of the movable charge is positive while the source charge is negative, or the movable charge is negative while the source charge is positive!

Now that I've justified negative electric potential energies mathematically, let's think about it conceptually. Electric potential energy is the energy transferred to a movable charge from an electric field if the charge were released and allowed to fly out to infinity. If the polarity of the source of the electric field has the same polarity as the movable charge, the potential energy will be positive as there would be a repulsive force between the two charges. However, if the two polarities were not the same, the source charge and movable charge would be attracted to each other. It would actually take an input of energy to move that particle out to infinity, and therefore that movable charge possesses a negative electric potential energy!

Answer 4

Answer:
Kinetic energy contains vectors, therefore it is a vector quantity, which means it contains both direction and magnitude information:
So, the vector component of the kinetic energy could be negative - yes! But the magnitude of the energy can never be less than zero.
Take this example:
you have a speed gun and you stand at the side of a road clocking the velocities of cars passing you. You estimate their mass, and work out their kinetic energies. If one car passes in one direction (say from right to left), you might say it has a + value, and a car going from left to right would have a negative value from then on. It could even be the other way around. All it means is that they are travelling in the opposite direction.
If you wanted to work out the total kinetic energy of two approaching cars, you would have to take the modulus value of the sum of the two kinetic energies, otherwise they would appear to cancel out, which would be misleading.
The thing to remember is you cant have negative magnitude of kinetic energy; there is no anti kinetic energy, as such. But you can have them travelling in opposite directions, where their velocities have opposite signs.

False

I belive your right Irlandaness, but you could have put more than the word false.

The reason is V^2 is always positive. -1*-1 = 1 -2*-2=4 so v^2 is a positive number and energy is a scaler. mass is always positive, therefore (1/2)m.V^2 is positive.

However, you can still get negative velocities in the way stated above (it is still important to realize).

Answer 5

The kinetic energy of a system can never be negative.

Lets look at the definition of kinetic energy:

KE = 1/2mv2

Mass can never be negative.

Velocity can be negative but squaring a positive or a negative equals a positive.

And so...

1/2 x positive x positive = positive

Answer 6

There are two answers to this question, "yes" and "yes, but..."

In a macroscopic and practical sense, kinetic energy is zero once it has zero velocity.

In a microscopic sense, any object with mass has kinetic energy inherently built into it. Atoms vibrate, electrons move, electrons spin, etc. To reach truly zero kinetic energy, there must be a total cessation of movement and reach a temperature of zero degrees Kelvin AKA Absolute Zero. While theoretically possible, this phenomenon has never been observed

Answer 7

KE = (1/2)m*v^2. Can mass or v^2 ever be negative?

Good question.

The answer is no.

Velocity is a vector whose sign indicates direction. So let's assume that the object is traveling in the negative direction (left or down by convention). Once a negative value is substituted for v and squared the answer will always be positive.

Mass cannot be negative either. That would mean you have less than nothing. Impossible.

Now consider negative energy.....So far I have not ever seen anyway to have less than zero energy. That would require the ability to have less than nothing. The concept of having less than nothing only works in accounting and imagination.

Energy and work on the other hand can have a negative value when doing the book keeping of flow and transformation of energy.

Answer 8

Yes. An object's potential energy is relative to an arbitrary constant. Depending on the choice of that constant, the potential energy can indeed be negative.

Answer 9

Yes.