T-bone: 'Helium has no weight'
From : transurgeontransurgeon
Q: it toward the earth it has no weight. helium does not have enough density or atomic weight for the force of gravity on this planet to hold it down so it has no weight here. im stupified here.... do you really believe that helium isnt dense enough for gravity to act on it huh holy shit! in the words of casey kasem... ponderous... fing ponderous.... helium doesnt posess any special anti-gravity properties tom... its just that the air around it is more dense and pushes the helium up... just like the oil in salad dressing pushes the vinegar to the top. please explain how matter can have mass but not have weight. given that gravity acts upon all matter i find this concept err... intriguing. take it and your co2 to the moon and neither will have any weight in gaseous form but they will both have the same mass there as they do here or anywhere else in the universe. since there is no atmosphere surrounding the moon both the helium and the co2 will sink to the lunar surface. .
Replies:
From : tom lawrence
are you saying that an airplane in the air weighs less than it does on the ground then you can add to that the fact if it is actually flying there is a force being applied to it that is negating the force of gravity the fact that an aircraft is supported by the application of bernoullis principle does absolutely nothing to lessen the force of gravity on the mass of the airplane. yes there is another force actually the same gravitational force that tries to pull the plane down is the same force that keeps it in the air thats working against the force of gravity but that doesnt mean the gravitational force no longer exists. just as if i took one end of a rope and you the other and we pulled against each other. if you pulled me forward that doesnt mean i wasnt pulling against you - just that you exerted more force than i did. weight. now i realize that this is an abstract thought process which seems hard for most of you to understand but it still is what it is. look up forces and vectors in a high school physics book... this is exactly whats being discussed here. .
From : tom lawrence
are you talking in a vacuum or under normal atmospheric conditions with air. either way it proves my initial point to dj before it became the distorted mess it now is which mass and weight are not the same thing. no - it proves you were wrong. you claimed it would have no weight remember ill bet that you will not be able to measure it. it can be measured... rather easily. why because it has mass. therefore it weighs something. in a vacuum at 1 atmosphere or at 10000psi - doesnt matter. that mass of helium not volume remember.. weighs 11.25lbs. here on earth. when contained in an environment such that its density is greater than the air around it it stays on the ground. if allowed to expand such that its density is less than the air around it it floats upward. this has nothing to do with weight because it weighs the same because the mass is constant and gravity is a constant. the fact that an object is bouyant does not mean it is weightless. .
From : dj
big al nospamsal1@qwest.net wrote 1992 dodge d50 ram 2.4 motor. has new coil/transtior for coil/mfi relay ecm rebuilt starter relay plus and wires cap /rotor/timing belt/head was warp has been shaved new gaskets.rebult dist /new ignition switch. rebult alternator.the problem is you turn key in start postion well start but you have to hard it in the start postion when released to run stops running so does anyone have and answer on what the problem is should could use help on this one the problem is in the ignition switch or the wiring. in the start position full battery voltage is fed to the ignition system for a hotter spark while cranking. after you release the key to the run position the voltage goes thru a resistor. dont really know the wiring of your vehicle but thats how it works. sometimes the full voltage is sent from the starter solenoid. try to get your hands on a manual and see. in your case the full voltage is there but the normal run voltage is not. al big al you win the award for best understanding of a post that was not at all understandable. .
From : joe brophy
can you then explain why the instructions from dodge for my 2003 dodge ram 3500 specifically states that the hitch be centered precisely over the centerline of the rear axle fwiw ive *never* encountered any lightening of the front end when *slowing* while towing my 14100# 5er. hint the leverage upon the frame that results from the vertical arm of the hitch support forces the front end *down* during deceleration. as a former long haul driver side lined by ms ill make some comments here. in your case you got a truck whose manufacturer has decided the optimum position for your model is over the center line. and that is assuming you load the trailer balanced. with the correct tongue weight for lack of a better word right now. the real test is the same we use with big rigs scale the axles. know what the front weight is empty and the rear axle. if you hook up and the front gains little or worse loses weight the king pin is too far back or the load is way out of balance. as for lightening of the front axle move the pin behind the axle and have good brakes on the trailer and the front end will get light. same thing can happen on a single screw tractor if the fifth wheel is slide back to far especially if the axles on the trailer are slide to far back. a little harder to have happen on a twin screw because the pin never slides beyond the rear axle most of the time wont even slide back over the rear axle. whitelightning .
From : miles
tom lawrence wrote so your current stance is that you can have weight without mass correct apparently you can have mass without weight too... as evidenced by the weightless helium gas that gravity doesnt act upon. that gets into understanding the difference between force and mass. when something is weighed its usually done in say lbf. if its lbm then local gravity and air bouyancy must be known. hmm...we should all go metric and just use newtons as our unit of measure. .