What is Kinetic energy: Definition and 1000 Discussions

In physics, the kinetic energy of an object is the energy that it possesses due to its motion.
It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.
In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is










1
2


m

v

2









{\displaystyle {\begin{smallmatrix}{\frac {1}{2}}mv^{2}\end{smallmatrix}}}
. In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.
The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound.

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  1. RyanJ

    I Energy Released From Dropping Things Onto Neutron Stars

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  2. I_Try_Math

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  3. P

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  4. Malwina

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  5. BikGer2

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  6. J

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  7. J

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  8. P

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  9. pineapplebanana

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  10. Lotto

    B Does a hot coffee have bigger mass than a cold coffee?

    As far as I know, something like relativistic mass is just a concept, just a trick, there is nothing like the relativistic mass. When I move faster, I have higher kinetic energy, but my mass is still the same as if I was at rest. Kinetic and potential energies do not increase object's mass. A...
  11. Venturi365

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  12. S

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  13. ValeForce46

    B Kinetic energy of quarks in a baryon

    If we say that a proton has a kinetic energy of ##50## GeV, can we say that each of the three quarks that compose it have roughly a mean energy of ##\approx\frac{50}{3}=17## GeV? If not, what can we say about the energy of each individual quark inside a baryon with a known energy?
  14. giodude

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  15. mazia

    Questions Regarding a Cat Going Up a Ramp

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  16. billard

    I Deriving formula for kinetic energy

    Hello! I am new to the differential version of classical physics, and I am trying to work how to derive kinetic energy from some pre-assumed equations: Assume that we know: ##\ddot{z} = 0## and ##m\ddot{\textbf{r}} \cdot \dot{\textbf{r}} = 0##This results in $$\frac{1}{2}m\dot{r}^2 = W =...
  17. A

    Work done during a collision -- Change in Kinetic Energy & change in Momentum

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  18. G

    Help me solve this integral for the equation of motion

    We have ##U(x) = U(a) + \frac{1}{2}U''(a)(x-a)^2## (by taylor series) It's known that ##U'(a) = 0## and point ##a## is a turning point, hence at that point, Kinetic energy is 0, and ##E = U(a)##, hence: We have ##U(x) = E + \frac{1}{2}U''(a)(x-a)^2##I need to get equation of motion and I want...
  19. Slimy0233

    B What is m in Kinetic Energy? Relativistic mass or Rest mass?

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  20. zachary570

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  21. E

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  22. xkcda

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  23. S

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  24. TonyCross

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  25. uSee2

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  26. L

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  27. KataruZ98

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  28. T

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  29. sinus

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  30. rogdal

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  31. KataruZ98

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  32. Muu9

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  33. J

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  34. vinicius_linhares

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  35. A

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  36. A

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  37. S

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  38. haha0p1

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  39. S

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  40. phos19

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  41. Differentiate it

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  42. earh1liw13w35sw5e

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  43. alichoudhry57

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  44. S

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  45. A

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  46. Ahmed1029

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  47. Rikudo

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  48. SkyeAlen

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  49. E

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