Recent content by omalleyt

Thanks, that saved me a lot of time trying to prove something that isn't true

I'm curious, can anyone think of a way to prove whether or not p^x - d^y = p - d, for any odd primes p,d and natural numbers x,y where x,y are not equal to one? This would be useful for a proof I am trying to work on. So far, I have found that 3^2 - 2^3 = 3 - 2, but for this proof I am...

Hi, I am looking for a 115 VAC motor (able to be plugged into an ordinary power outlet) that is capable of raising and lowering a load of up to 150 lbs. (attached to a cable and a pulley) at the speed of 6 inches per second. I want the speed to remain constant even if the load changes. How can I...

Say I have an AC motor with 100 ft*lbs torque, and I run it against a load of 200 ft*lbs torque so that the motor spins in the opposite direction of the power it is providing. Is this possible, and if so can this condition be sustained over a period of time without damaging the motor?

I have a system where a cable is pulled down with a load of 100-200 lb. I need a motor that resists this load with a force that can be programmed to be anywhere from 5-30 pounds. I don't want the motor to stop the downward motion, just to offset the magnitude of the force pulling down on the...

I have 5 different types of balls made out of different materials, all similar but not identical in weight, and all of the the same size. What is the best mechanism to sort these by weight? I can use any mechanical device to sort these balls, such as seesaws, etc. What is the most efficient way?

What is the best way to distinguish and separate chrome steel, carbon steel, and stainless steel? I.e., if I had balls of chrome steel, carbon steel and stainless steel that were all of the same size, how could I tell them apart? The weights of the materials are very similar, and I am looking...

What is the pattern that maximizes the ratio of surface area of a flat surface to the volume of material used in this surface? The surface has to be flat on a macroscopic scale, but on the microscopic scale could have dimples or other imperfections that increase the SA/Volume ratio. I am...

Alright. I need a motor that is capable of pumping air into a piston filled with compressed air. The motor needs to pump the air into the piston at a constant speed, as the piston is being used to raise up a load. The problem is that the weight of the load on the piston will be between 10-200...

I need to find or design an apparatus, consisting of a wire and a load hanging from the wire, that can resist the load in such a manner as that no matter what the mass of the load is the load will move downwards at a velocity of 1 m/s. The load will be between 5 and 300 lbs. I am open to using...

Ok, here's a description of what I'm trying to achieve. I want to design a wire apparatus that lowers a weight using the mass of the weight as the force, but then somehow achieves a balance of forces when the velocity reaches 1 m/s. This is simple enough using friction (I think), but the problem...

Ok. Sorry, you guys are right my first question was really vague. Here's a better description of what I'm trying to achieve. I want to design a wire apparatus that lowers a weight using the mass of the weight as the force, but then somehow achieves a balance of forces when the velocity reaches...

How can I make a hanging weight attached to a wire move at a constant speed under its own weight? The mass of the weight may vary and is not known beforehand.

How much (approximately) would the DC motor weigh, and would it be able to withstand the 500lb load?

Hi. For a project of mine, I need a motor that can dole out and pull in a wire at a constant speed under a dynamic load. The load will be anywhere between 20-500 lbs. The speed will be about 1 ft/sec. Any idea about how I can achieve this effect? Is a motor even the right way to go or should...