How much energy does it take...
| Guest |
Saturday, October 8, 2011 at 6:04 AM |
Does it take the same amount of energy to inflate a tyre to a specified pressure when it is attached to the car on the ground, as opposed to when the car is jacked up and there is no weight on the wheel?
| Guest |
Thursday, October 13, 2011 at 6:46 AM |
it will take more energy since extra work should be done against wt.
| Guest |
Thursday, October 13, 2011 at 6:51 AM |
in 2nd to jack up the car energy will require.
| Guest |
Friday, October 28, 2011 at 3:08 PM |
it may take more energy off the car as it will take a greater volume of air to reach the same pressure
| Guest |
Wednesday, November 9, 2011 at 3:47 PM |
40 lbs of pressure....is 40 lbs of pressure....same energy....I think...lol
| Guest |
Tuesday, March 20, 2012 at 10:50 AM |
I'd say the same as it is the same amount of pressure being pumped into the tyre...
| Guest |
Thursday, October 23, 2014 at 6:57 PM |
@Curtis: this has nothing to do with energy. If you put a tyre on the ground, the air in the tire is compressed by the weight of the vehicle. This does not increase the amount of energy in the tire (at least not for a Long time: the compression creates heat, which is then dispersed in the environment). Actuall, the amount of energy in the tire evcven decreases a Little (after the heat is dispersed), because the average distance between the particles in the tire and ground gets less, which means that it has contains potential energy (because of the same reason, a vehicle which stands at an higher altitude has more energy, you can use this energy to drive it down fast without using any fuel if the altidue difference and gradient of the track is high enough).
The reason why a weak compressor cannot pump up a tire that stands on the ground is that every compressor has a Maximum pressure, so if you want to inflate the tire to a pressure which is higher than the Maximum pressure of the compressor, it doesn't work. The pressure of the tire is less with the same amount of air in the tire, if their is no weight on the tire.
In the maayonnaise jar example you actually Need less amount of energy if you do bring the air in the baloon to the same pressure if the baloon is inside the jar: same pressure, but less volume. Actually for an ideal gas, the formula is P*V = N*k*T = (2/3)*k*E. P = pressure, V = volume, N = number of molecules, k = Boltzmann constant, T = temperature, E = (thermal) energy (E=(3/2)*N*k*T).
| Guest |
Thursday, October 23, 2014 at 6:59 PM |
PS: I forgot to mention: air at room temperature (~300K) is almost an ideal gas.
| Guest |
Thursday, October 23, 2014 at 7:01 PM |
PPS: at least if you also have a "normal" pressure. Normally tires are pumped up to less than 10 atmospheres, which is still in the Region where the behavior is almost the same as of an ideal gas (this is true up to about 100 atmospheres).
| Guest |
Thursday, October 23, 2014 at 7:15 PM |
Actually it is disputed if Smith abandoned the Titanic, it is only known that he did not survive.
However "Captains never Abandon a ship" is idealistic, but unrealistic. In reality it happens very often that a captain Abandons his ship even before everyone is rescued, a more recent example is the captain of the Costa Concordia.
The reason why Smith was so careless was probably arrogance about the ship: Smith thought (like many other preople) that the RMS Titanic was "unsinkable". He was not responsible for the number of lifeboats on the Titanic, the number of Lifeboats was limited by design and was not decided by the captain.
| Guest |
Thursday, October 23, 2014 at 7:15 PM |
Sorry, the postng System doesn't work corectly,. it posted my previous answer on the wrong page...
