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# Physics/Force needed to move a cart

Question
I'd like to know how much force it takes to push a food cart from sitting still to pushing it 40 feet to an elevator for food delivery.  The empty cart weight is 430 pounds and has 4 swivel casters on each bottom corner and two swivel casters, one on each bottom side, in the middle of the cart frame.  The cart will be loaded with 50 food trays that weigh 8 pounds each. This is a total of 830 pounds.  Cart dimensions are 62 inches high, 60 inches long and 31.5 inches deep. I am 74 inches tall and weigh 265 pounds.

The cart is pushed by myself without any assistance.  I assume it takes additional initial force to get the cart rolling.

I would appreciate the answer (s) being in pounds of force if possible.

That is one massive food cart!  The problem is that you've answered a question which cannot be answered.  There's no information about the friction of the wheels, how fast the cart gets, or anything at all that would make calculating the answer possible.  So at least I know this is not a homework question, since if it were it would be impossibly badly posed.

To answer a question like this, you really do need to know about friction from the wheels and how fast it gets (and over what distance it gets up to its top speed).  If the wheels were frictionless and you could wait a really long time to get the cart to the elevator, very little force would be needed to get it there at all.  If you want to get it moving at its top speed within a few inches of pushing it or you have higher-friction wheels (especially at 830 pounds), then you need a lot more force.  Your height and weight are actually irrelevant unless you have a good measurement of friction on the wheels and can tell me at what height you push on the cart itself.

Short of knowing these things, the only way to find out is to go and measure it (such as by pushing the cart with a bathroom scale and taking the maximum reading).  It's just not possible without making assumptions for the aforementioned quantities.

Physics

Volunteer

#### Dr. Stephen O. Nelson

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I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.

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I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Education/Credentials
Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.