An object which moves in the negative direction has a negative velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion in this case, a positive acceleration.
The air fluid resistance force on an object depends primarily on: the relative velocity of the object and the fluid. For very small objects — microscopic to dust mote size — air resistance force is approximately proportional to velocity, v. The aerodynamic force equals a constant times the density times the velocity squared. Skip to content Why is kinetic energy velocity squared?
Is kinetic energy proportional to velocity? Does kinetic energy use velocity or speed? Is velocity squared equal to acceleration? Why is force proportional to velocity squared? What is the relationship between kinetic energy and velocity 2? Is velocity a vector or scalar?
Why is kinetic energy scalar? Is force a scalar quantity? Is kinetic energy is directly proportional to pressure? What factors s affect kinetic energy?
Which is the best example that something has kinetic energy? Does speed affect kinetic energy? Does height affect kinetic energy? Does mass affect velocity?
Mass does not affect the speed of falling objects, assuming there is only gravity acting on it. Why is kinetic energy never negative? What is kinetic energy when velocity is doubled? Comment god particle god particle: So glad to hear from you. According to my assumptions, you were not supposed to exist.
The velocity of the microcosm has to decrease from v to 0. In either case, we must hold fast to the Fifth Assumption of Science, conservation Matter and the motion of matter can be neither created nor destroyed and the Fourth Assumption of Science, inseparability Just as there is no motion without matter, so there is no matter without motion.
When the macrocosm presents an impenetrable barrier, the motion of the microcosm stops. Whether calculated as either momentum, force, or kinetic energy, all will be reduced to zero during the collision when the velocity drops to zero. According to conservation, of course, that motion must go somewhere, perhaps as internal submicrocosmic motion of the microcosm and vibratory motion of the macrocosm.
If the microcosm was a vehicle, we would use the brakes to decrease its velocity to zero. The motion of the vehicle is transmitted to the brakes, tires, and pavement, generally appearing as the vibratory motion we call heat. Again, the second v shows up in the equation because we use it to calculate the displacement produced by the collision. Post a Comment. From henk:. Glenn, thanks for your answers. I am still thinking about kinetic energy.
In the 17th century, experiments by Willem Jacob 's Gravesande showed that the striking of a ball in clay was proportional to squared velocity and later on a French physician showed it was proportional to 'mass times squared velocity'. What is it about, is my question?
How to get the formulae not by math manipulation, but from experimental considerations? By the way, I explained to a friend the idea of matter-motion by using examples and despite he is a dummy in math and physics, the matter-motion explanation seems to be more appropriate to grasp physics even at his age of Thanks again for the comment.
Before the Gravesande experiment, one would have thought that doubling the velocity of a microcosm would result in double the impact. Not so. As you mentioned, the doubling of velocity causes four times the impact.
In other words, a microcosm impacting a soft, wet clay at velocity 2v will create a crater 4 times as deep as a microcosm impacting the clay at velocity v; an auto crashing into a wall at 40 mph will suffer 4 times the damage as one crashing into a wall at 20 mph. Your question: What gives? I am afraid that this is one occasion in which I will not be able to avoid math, as much as I would like too. The simple reason that velocity is squared is the fact that there is a macrocosm.
This observation, the law of the universe, makes Newton the most brilliant scientist who ever lived. Motion With a Macrocosm. While the First Law is just an astute observation concerning inertia, this Second Law describes causality.
A cause produces acceleration, that is, a change in velocity. The force concept is a handy, necessary mathematization.
It is especially useful when we really do not know the actual cause. The true cause of the acceleration of any particular microcosm must be at least one other microcosm that collides with it.
Incidentally, this is why determinists deny the possibility of ESP. Notify me of follow-up comments by email. Notify me of new posts by email. There's a book! It's a collection of over fifty of my favorite articles, revised and updated. It's interesting. It's good. You should buy it. Click the photo for a link to the amazon page, or this link for the ebook.
Email Address. Skip to content. Home About Faq. Q: After the heat death of the universe will anything ever happen again? Q: Why does kinetic energy increase as velocity squared? Posted on March 2, by The Physicist. Email Print Facebook Reddit Twitter. This entry was posted in -- By the Physicist , Physics. Bookmark the permalink. Bob Berenz says:. March 17, at am. Pablo Jeynes says:.
April 23, at pm. Larry Phillips says:. September 8, at am. A high school, non-calculus, version of an answer is this: Imagine pushing a mass m with a constant force F through a distance d. September 15, at am. Angel says:. November 26, at pm. Gregory Kress says:. October 20, at am. DavidB says:. February 16, at am. Danshyl Boodhoo says:.
October 3, at pm. Andy B says:. November 8, at pm. November 9, at am. Danshyl and all, Oh, thank you!! Stuart Hunt says:. July 4, at am. Garcia A. April 24, at am. I have other intuitive ideas: 1 a balance, with one plate twice as long as the other, would require twice the weight on the sort plate in order to maintain equilibrium.
Pablo says:. September 17, at am. September 18, at am. Leave a Reply Cancel reply Your email address will not be published.
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