# Calculating how fast a motor can move something in horizontal motion

by caljuice
Tags: horizontal, motion, motor
 P: 67 1. The problem statement, all variables and given/known data So I need a motor for a project. The motor i'm looking at creates circular motion. I want to make the motor move some object in a horizontal motion but I want to know how fast it can move the object horizontally before getting it. How can I find out how fast the motor can move it? Motor in mind: http://www.servodatabase.com/servo/hitec/hs-322 Sorry if there are unnecessary unit conversions. Seems like engines are explained in imperial units. 2. Relevant equations Using this equation to find horsepower = (Torque x Engine speed (rpm)) / 5,252 = Horsepower Found from:http://www.howstuffworks.com/question622.htm Torque for engine = 3.70 kg*cm = 0.03 kg per m = 0.22 lb/ft speed = 0.15 sec/60° (not really sure what this is? Assuming 60 degrees every .15 sec. So one revolution (360 degrees) = 0.15 sec x 6 = .90 sec. Then rpm = 66.7 Mass of object being rotated =0.2 kg 3. The attempt at a solution One way I thought of calculating this was converting the torque output to Power then converting power to work then to kinetic energy to velocity. Horse power = 0.22 * 66.7 /5252 = .0028 horse power Mechanical horse power = 33,00 lb*ft/min so (0.028 * 33,000)/60s= 1.54 lb*ft =2.09 n*m I'll assume all work will equal KE. 2.09 J = 0.5 *0.2*v2 V= 4.6m/s. Does it look right? Any help would be appreciated.
 PF Patron HW Helper P: 3,780 Think about this: you said 'horizontal' motion. What if anything limits the velocity if you continually apply a certain amount of power to a mass moving horizontally? BTW on the rhs equation of 'mechanical horse power' the dimension is energy, not power, so I would check that. Always check dimensions on any work you do. Every single term. I find more mistakes I make that way than with any other, by a mile!
P: 67
 Quote by rude man Think about this: you said 'horizontal' motion. What if anything limits the velocity if you continually apply a certain amount of power to a mass moving horizontally?
I'm guessing you mean drag and friction? Would it still affect it a lot with the device being so small? I don't think I would be able to calculate it with the information I'd have.

 Quote by rude man BTW on the rhs equation of 'mechanical horse power' the dimension is energy, not power, so I would check that. Always check dimensions on any work you do. Every single term. I find more mistakes I make that way than with any other, by a mile!
Sorry isn't it in energy already? 2.09 Nm is Joules.

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