Home |
Search |
Today's Posts |
#171
![]() |
|||
|
|||
![]()
Gene Fuller wrote:
Electrical potential energy has units of voltage multiplied by charge. Voltage by itself is not potential energy, literally or otherwise. I didn't mean to imply that voltage and energy are the same thing. But voltage is indeed literally potential energy (per unit charge). -- 73, Cecil http://www.qsl.net/w5dxp |
#172
![]() |
|||
|
|||
![]()
"Cecil Moore" bravely wrote to "All" (21 Dec 05 23:25:05)
--- on the heady topic of " Antenna reception theory" CM From: Cecil Moore CM Xref: core-easynews rec.radio.amateur.antenna:221661 CM Asimov wrote: Voltage is kind of like having a big boulder sitting on top of a high cliff. CM Yep, it is. A big boulder sitting on top of a high cliff CM contains a lot of potential energy. Voltage is literally CM potential energy and cannot exist without energy. If I can manage to roll the boulder up at the top or at the bottom of the cliff, I will find it weighs about the same. The boulder only picks up energy as it is accelerating towards the foot of the cliff. A*s*i*m*o*v |
#173
![]() |
|||
|
|||
![]()
Asimov wrote:
"Cecil Moore" bravely wrote to "All" (21 Dec 05 23:25:05) --- on the heady topic of " Antenna reception theory" CM From: Cecil Moore CM Xref: core-easynews rec.radio.amateur.antenna:221661 CM Asimov wrote: Voltage is kind of like having a big boulder sitting on top of a high cliff. CM Yep, it is. A big boulder sitting on top of a high cliff CM contains a lot of potential energy. Voltage is literally CM potential energy and cannot exist without energy. If I can manage to roll the boulder up at the top or at the bottom of the cliff, I will find it weighs about the same. The boulder only picks up energy as it is accelerating towards the foot of the cliff. A*s*i*m*o*v W R O N G !!!!!!!!!!!!!!!!!!!!! The boulder has energy simply because it is on top of the cliff. [Potential Energy]. As it accelerates towards the bottom of the cliff the energy changes [ CHANGES ] from POTENTIAL to KINETIC. The 11th commandment: Energy can be neither created nor destroyed: just changed in type of energy. A*s*i*m*o*v, you need to refresh your freshman University Physicss. AK |
#174
![]() |
|||
|
|||
![]()
Asimov wrote:
If I can manage to roll the boulder up at the top or at the bottom of the cliff, I will find it weighs about the same. The boulder only picks up energy as it is accelerating towards the foot of the cliff. Energy cannot be created or destroyed. The kinetic energy gained as it accelerates is exactly balanced by the loss in potential energy that it had at the top of the cliff. Consider a pendulum. When it stops at the limit of its swing, it possesses potential energy. When it is moving at its fastest at the bottom of its swing, it possesses kinetic energy. When it finishes the swing to the other limit, it possesses potential energy. Neglecting losses, potential energy at the top of the swing is converted into an equal magnitude of kinetic energy at the bottom of the swing and back to potential energy at the top of the swing. -- 73, Cecil http://www.qsl.net/w5dxp |
#175
![]() |
|||
|
|||
![]()
"Cecil Moore" bravely wrote to "All" (22 Dec 05 14:47:46)
--- on the heady topic of " Antenna reception theory" CM From: Cecil Moore CM Xref: core-easynews rec.radio.amateur.antenna:221698 CM Asimov wrote: If I can manage to roll the boulder up at the top or at the bottom of the cliff, I will find it weighs about the same. The boulder only picks up energy as it is accelerating towards the foot of the cliff. CM Energy cannot be created or destroyed. The kinetic energy gained CM as it accelerates is exactly balanced by the loss in potential CM energy that it had at the top of the cliff. CM Consider a pendulum. When it stops at the limit of its swing, CM it possesses potential energy. When it is moving at its fastest CM at the bottom of its swing, it possesses kinetic energy. When CM it finishes the swing to the other limit, it possesses potential CM energy. Neglecting losses, potential energy at the top of the CM swing is converted into an equal magnitude of kinetic energy at CM the bottom of the swing and back to potential energy at the top CM of the swing. Consider the Earth-Moon system, they interact via the oceans on Earth. The water level bulges can be considered as the pendulum in your example. The result of the tide is that gravitational energy is being transfered to the Moon and it is gradually accelerating away from the Earth. So in your example the pendulum doesn't have any energy except that which it borrows and returns to the Earth's pull of gravity. If we were to follow your logic the Moon should fall to the Earth instead. Assuming frictionless bearings and zero drag your pendulum should go on forever because it has no energy of its own. A*s*i*m*o*v |
#176
![]() |
|||
|
|||
![]()
Asimov wrote:
"Cecil Moore" bravely wrote to "All" (22 Dec 05 14:47:46) --- on the heady topic of " Antenna reception theory" CM From: Cecil Moore CM Xref: core-easynews rec.radio.amateur.antenna:221698 CM Asimov wrote: If I can manage to roll the boulder up at the top or at the bottom of the cliff, I will find it weighs about the same. The boulder only picks up energy as it is accelerating towards the foot of the cliff. CM Energy cannot be created or destroyed. The kinetic energy gained CM as it accelerates is exactly balanced by the loss in potential CM energy that it had at the top of the cliff. CM Consider a pendulum. When it stops at the limit of its swing, CM it possesses potential energy. When it is moving at its fastest CM at the bottom of its swing, it possesses kinetic energy. When CM it finishes the swing to the other limit, it possesses potential CM energy. Neglecting losses, potential energy at the top of the CM swing is converted into an equal magnitude of kinetic energy at CM the bottom of the swing and back to potential energy at the top CM of the swing. Consider the Earth-Moon system, they interact via the oceans on Earth. The water level bulges can be considered as the pendulum in your example. The result of the tide is that gravitational energy is being transfered to the Moon and it is gradually accelerating away from the Earth. So in your example the pendulum doesn't have any energy except that which it borrows and returns to the Earth's pull of gravity. If we were to follow your logic the Moon should fall to the Earth instead. Assuming frictionless bearings and zero drag your pendulum should go on forever because it has no energy of its own. A*s*i*m*o*v A*s*i*m*o*v, Man you gotta be kidding !!!!!! The tides are responding to the gravitational reaction of the earth-moon gravitational system; not causing them!!!!!!!! Yep, in the absence of centripetal acceleration the moon would crash. But, isn't nature wonderful!! The moon has just enough centripetal acceleration to keep it from falling into the earth. The sum of forces on the moon keep it from flying into space or from falling to earth. As I said in a previous post; You need to refresh your University Physics 101. AK |
#177
![]() |
|||
|
|||
![]()
Amos Keag wrote:
The sum of forces on the moon keep it from flying into space or from falling to earth. Actually, that's only short term. The moon is presently receeding and will someday reverse that trend and indeed fall to earth. -- 73, Cecil http://www.qsl.net/w5dxp |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Inverted ground plane antenna: compared with normal GP and low dipole. | Antenna | |||
significance of feedline orientation | Shortwave | |||
Question for better antenna mavens than I | Shortwave | |||
QST Article: An Easy to Build, Dual-Band Collinear Antenna | Antenna | |||
Outdoor Scanner antenna and eventually a reference to SW reception | Shortwave |