2007-08-26 10:10:15 · 10 answers · asked by I hate Hillary Clinton 6 in Science & Mathematics ➔ Engineering
Elevators have a design limit for a weight load in the car. When designing the elevator there are 3 weights to consider.
First there is the carriage itself including the cables that suspend it. Since the cable length is variable, the maximum cable possible is used. Second, there is the counterweight, this has a specific weight and function which I will cover shortly. The third weight is the actual load of people and stuff in the carriage.
The counterweight's function is to counter the weight of the carriage and it's load to reduce the work required by the motor. Ignoring the weight of the cable, the counterweight is set with a weight of carriage plus half of the max elevator load. This means that if the elevator has a load of half of it's capacity, the motor will be doing very little work!
Another interesting fact of elevators is that it takes the same amount of work to pull a fully loaded carriage up as it does to move an empty carriage down.
The reason that the weight of the cables come into play is that the highest load on the motor comes with accelerating a fully loaded carriage upwards from the lowest floor as well as acceleration an empty carriage down from the top floor. These need to be factored in when choosing the parts to build the system.
What happens if the elevator is overloaded? A warning is typically set and a lamp that states "overload" or other wording lights. The weight can easily be measured to detect such a situation. Typically, the system is designed to handle more than it's capacity by some margin but won't budge unless the weight is below the set point. I often find that elevators won't fit it's capacity of weight into the carriage under most circumstances. From time to time I've seen the overload lamp.
All of the above is used to answer your question. If an elevator is moving a load upwards, it will never work any harder than it does to move an empty carriage down. The elevator will stay locked in place if the load is too great and won't move. Most of the time when the elevator is moving a load, it's a partial load.
2007-08-26 13:52:21 · answer #1 · answered by Anonymous · 2⤊ 0⤋
Elevators are rated for the maximum total load they can lift at a time. If a lot of obese people got in at the same time (like maybe those friends of Jon Pinette he talks about escaping from Weight Watchers to raid the buffet) then the elevator would more quickly reach its maximum weight capacity. But it is hard to reach that number in a typical office elevator so this is not a real problem. If it was overloaded it would just stay there and beep until someone stepped off and brought the total down.
2007-08-26 21:10:41 · answer #2 · answered by Rich Z 7 · 0⤊ 0⤋
Elevators are designed to lift a specific load. They have no problem lifting a load with in the design range. FYI two skinny people weight more than one fat. So it really does not matter if the person is skinny or fat. Its the design load limit that must not be surpassed.
PS. I have never seen a passenger elevator rated for 15,000 lbs, I have seen one for 3000 lbs. I think that is the limit but this is from a old flaky memory.
And the elevators have no problem lifting the rated loads.
2007-08-26 17:59:29 · answer #3 · answered by Anonymous · 4⤊ 0⤋
Yes, the actual load on the motor goes up with the weight of the people (person) inside the elevator car.
But, considering the empty car itself weighs at least 10 times what a normal person does, the difference between a 150 lb. person and a 200 lb (overweight) person is something on the order of 1% of the total, so 1% more load it isn't *that* much harder on the motor.
.
2007-08-26 17:17:58 · answer #4 · answered by tlbs101 7 · 2⤊ 2⤋
NO, fatties or skinny's it doesn't matter. each elevator is rated for "Weight", that being a total. Some elevators will say they are capable of 6 people, generally that is figured a 6X180 or 1,080 pounds.
2007-08-26 18:08:16 · answer #5 · answered by Anonymous · 0⤊ 1⤋
Yes. They weigh more and put a greater load on the motors. Whether anything happens as a result is quite unlikely.
2007-08-26 17:19:38 · answer #6 · answered by qin137 2 · 2⤊ 0⤋
All other considerations aside it takes more energy to lift more mass.
PE = mgh
for more see source below.
2007-08-26 18:40:43 · answer #7 · answered by Dan Peirce 5 · 0⤊ 0⤋
Most elevators can carry up to 15000 pounds.
I'm sure it will be able to carry an average obese fatty which is like 300 pounds.
2007-08-26 17:12:34 · answer #8 · answered by Anonymous · 2⤊ 5⤋
yes
2007-08-26 17:18:04 · answer #9 · answered by Lov'n IT! 7 · 1⤊ 1⤋
no its the same thing as having more ppl the pressure it always the same!!
2007-08-26 17:17:30 · answer #10 · answered by Gippy 4 · 0⤊ 2⤋