The time derivative of kinetic energy

Therefore, ##\frac{dp}{dt} = \vec{F}## and using the chain rule, ##\frac{dT}{dt} = \frac{1}{2m}2p\frac{dp}{dt} = \frac{1}{2m}2p\vec{F} = \vec{v}\cdot \vec{F}##. In summary, we can see that ##\frac{dT}{dt}=\vec{v}\cdot \vec{F}## from considering the equations for kinetic energy and Newton's second law.
  • #1
LagrangeEuler
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Lets consider [tex]T(\vec{p})=\frac{\vec{p}^2}{2m}=\frac{\vec{p}\cdot \vec{p}}{2m}[/tex]. Then [tex]\frac{dT}{dt}=\vec{v}\cdot \vec{F}[/tex].
And if we consider
[tex]T=\frac{p^2}{2m}[/tex] than [tex]\frac{dT}{dt}=\frac{1}{2m}2p\frac{dp}{dt}[/tex]
Could I see from that somehow that this is [tex]\vec{v}\cdot \vec{F}[/tex]?
 
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  • #2
LagrangeEuler said:
Lets consider [tex]T(\vec{p})=\frac{\vec{p}^2}{2m}=\frac{\vec{p}\cdot \vec{p}}{2m}[/tex]. Then [tex]\frac{dT}{dt}=\vec{v}\cdot \vec{F}[/tex].
And if we consider
[tex]T=\frac{p^2}{2m}[/tex] than [tex]\frac{dT}{dt}=\frac{1}{2m}2p\frac{dp}{dt}[/tex]
Could I see from that somehow that this is [tex]\vec{v}\cdot \vec{F}[/tex]?
Well, ##\vec {p} = m \vec {v}## and ##\vec F = \frac{d\vec p}{dt}## is Newton's second law.
 
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1. What is the definition of the time derivative of kinetic energy?

The time derivative of kinetic energy is the rate of change of an object's kinetic energy with respect to time. It is represented by the symbol dK/dt, where K is the kinetic energy and t is time.

2. How is the time derivative of kinetic energy related to an object's motion?

The time derivative of kinetic energy is directly related to an object's motion. It represents the amount of work being done on the object per unit time, which is equal to the net force acting on the object multiplied by its velocity.

3. What is the formula for calculating the time derivative of kinetic energy?

The formula for calculating the time derivative of kinetic energy is dK/dt = F * v, where dK/dt is the time derivative of kinetic energy, F is the net force acting on the object, and v is the velocity of the object.

4. How does the time derivative of kinetic energy change over time?

The time derivative of kinetic energy can change over time depending on the net force acting on the object. If the net force is constant, the time derivative of kinetic energy will also be constant. However, if the net force changes, the time derivative of kinetic energy will also change.

5. What is the significance of the time derivative of kinetic energy in physics?

The time derivative of kinetic energy is a key concept in physics as it helps us understand the relationship between an object's motion and the forces acting on it. It is also used in many equations and principles, such as the work-energy theorem and Newton's second law of motion.

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