Potential energy of a falling object

[rednewguy]

potential energy

i am throwing an object upwards.

at certain point, where the kinetic energy is zero and potential energy is maximum, the object stops ascending and starts descending.

at this point, if i forcibly spend all the potential energy, will the object be able to fall down.
what will happen?

thanks

 

[mehboob_iiui]

Re: potential energy

The object posseses p.e due to its height, it it has the height it will retain its potential, the only i know to spend this energy is to convert it to kinetic , by making it lose height

 

[invent]

Re: potential energy

I agree, because the object posseses p.e due to its height or gravity acting on the object. this is unless you spend more energy to break the gravity hold.

 

[rednewguy]

Re: potential energy

is there no other way to convert the potential into kinetic without reducing the height.

 

[ivar4ever]

Re: potential energy

if u are not going reduce the heightm the potential energy wont reduce.
i believe there is no other go to reduce the PE apart from reducing the height.

 

[Harmasha]

Re: potential energy

Think about this fiction.
Some Sacred men uplift themselves in air and Float. Then this should be similar to what you are saying about.
Also This potential energy is due to Earth's gravity alone.
PE = mgh (mass*height*gravity). So the mass has to be considerably reduced for the object to retard its fall.
Again this is not independant for the acceleration due to gravity increases as the object is descending giving rise to Inertia to stop its fall.
Then in the first case (fiction) the uplift is achieved by lowering mass of the body.
Again considering mass to be absolute. Then the only way is PE is increased. So then IS there a conversion of K.E. to P.E.

(Nice topic Rednewguy).

 

[dfullmer]

Re: potential energy

You guys are making me think to early in the morning. Isn't potential energy relative? The potential energy of the object is in relation to the earth. It also has potential energy in relation to the sun, planets, stars...etc. Interesting to think about. I don't think you can ever eliminate potential energy just change its reference.

Or maybe I just need more coffee.


dfullmer

 

[Harmasha]

Re: potential energy

Hi,
Think of the concept of UFOs.
They rotate to mantain height. So if you want to maintain the ball at a certain height, then one thing is that you start giving it kinetic energy, or derive rotational motion for this release of kinetic energy should make the PE zero and make it float.

 

[jallem]

potential energy

The important thing here is how you are going
to "take out" the potential energy, spend as you
said. If you can do
that then the object will float, or in others words
would be an anti-gravitational system. If you can
do that you will win the Nobel prize...!!!!!!!

 

[Harmasha]

Re: potential energy

Hi,
Ya the principle of hovercraft should work here right???
Any way the spinning should be made a stable or an equilibrium system with a central high gravity object that pulls the periphery of the outer rotor so that a centripetal force is created artificially. Can this idea be build.