| General > General Technical Chat |
| Electroboom: How Right IS Veritasium?! Don't Electrons Push Each Other?? |
| << < (112/148) > >> |
| Naej:
--- Quote from: electrodacus on July 15, 2022, 11:33:50 pm ---Case: A) vehicle speed is 2m/s so lower than wind speed and the wind speed relative to vehicle will be 4m/s B) vehicle speed equals wind speed so 6m/s that means wind speed relative to vehicle is 0m/s C) vehicle speed higher than wind speed at 10m/s and it this conditions vehicle can not accelerate forward. So unless you think I used the wrong equations the 3 cases show A) vehicle can accelerate forward when vehicle speed is below wind speed B) vehicle can ideal case just stay at wind speed and C) vehicle can only slow down/decelerate. --- End quote --- You chose F_M=F_G so in all cases the vehicle does not accelerate. However in cases A) and C) you have 20W & 4W to spare so it shows that you can extract energy from 2 objects moving at different speeds, a fact that is indeed true, and that you can see everywhere (wind turbines, water turbines, regenerative braking, etc.). In case B) you can choose any F_M of course, so you can choose your acceleration. |
| electrodacus:
--- Quote from: Naej on July 16, 2022, 12:24:56 am ---You chose F_M=F_G so in all cases the vehicle does not accelerate. However in cases A) and C) you have 20W & 4W to spare so it shows that you can extract energy from 2 objects moving at different speeds, a fact that is indeed true, and that you can see everywhere (wind turbines, water turbines, regenerative braking, etc.). In case B) you can choose any F_M of course, so you can choose your acceleration. --- End quote --- There is no choice other to have those forces equal. There is no onboard energy storage or energy source. You can only have a value for FG if you have an equal and opposite force (Newton's 3'rd law). There is a +20W net for case A) so vehicle will be accelerated from left to right. For case C) there is a -4W net meaning vehicle will move from right to left. |
| Naej:
--- Quote from: electrodacus on July 16, 2022, 12:34:00 am --- --- Quote from: Naej on July 16, 2022, 12:24:56 am ---You chose F_M=F_G so in all cases the vehicle does not accelerate. However in cases A) and C) you have 20W & 4W to spare so it shows that you can extract energy from 2 objects moving at different speeds, a fact that is indeed true, and that you can see everywhere (wind turbines, water turbines, regenerative braking, etc.). In case B) you can choose any F_M of course, so you can choose your acceleration. --- End quote --- There is no choice other to have those forces equal. There is no onboard energy storage or energy source. You can only have a value for FG if you have an equal and opposite force (Newton's 3'rd law). There is a +20W net for case A) so vehicle will be accelerated from left to right. For case C) there is a -4W net meaning vehicle will move from right to left. --- End quote --- Did you read Newton's laws? |
| cbutlera:
--- Quote from: electrodacus on July 15, 2022, 02:45:32 pm --- OK so you want to look at this with vehicle body as reference. See the 3 examples below and let me know if you think any of the equations are wrong. (Attachment Link) --- End quote --- That is a nice diagram, although there are some errors in the equations. For the purposes of this thought experiment, the vehicle is assumed to be travelling at a constant velocity. The question being asked is whether there is any net power remaining that could be used to accelerate the vehicle. The first equation error is that FM should be equal to -FG. The two forces must be of equal magnitude but opposite direction, if the vehicle is to remain at a constant velocity. The second equation error is the inclusion of the Pin term in the equation for Pout. The motor knows nothing about Pin other than the force FG that it has to compensate for. The third equation error is the sign of Pnet. The net power remaining is equal to the power provided by the generator, less the power consumed by the motor, not the other way around. With these corrections, Pout will be negative in case A), the below wind speed case. In other words the motor will be acting as a generator, as would be expected. In case C), the above wind speed case, Pout will now be 4W. So a power Pnet = 6W will remain and could be utilised to accelerate the vehicle. |
| electrodacus:
--- Quote from: Naej on July 16, 2022, 08:44:11 am ---Did you read Newton's laws? --- End quote --- So are you saying that Newton's 3'rd law (for every force there is an equal and opposite force) does not apply for some reason to my three examples ? I will love to hear the reason. This is maybe as important as the law of conservation of energy in understanding how this wind powered vehicle works. If you disagree with my calculations and or conclusions then show what you think it will happen especial for case C) As it is that vehicle is nothing more than a gearbox with input connected to Road treadmill and the output connected to Wind treadmill and importantly the case of the gearbox (vehicle body) is not connected to anything. |
| Navigation |
| Message Index |
| Next page |
| Previous page |