jwest22

I've been getting confused between velocity and acceleration. If the intial velocity is 0 and the final velocity is 0.025m/s over 10s, the the accelleration: a=0.0025m/s^2 So, where does that leave me with the force, presumable not just f=ma as that would equate to 0.02newtons?

Sorry, I wrote that in a really stupid way. Let me try and rephraise it. If an object is sitting on a surface, and a piece of string is attached to the object with an 8kg weight on other end, the weight is then dropped off the edge of the surface, and the object is pulled along at 0.025m/s (friction can be ignored). Therefore how much force is needed to move that object? Does that makes any sense, or have I just made a total hash of it?

Hello, im struggling with what should be a simple problem but I just cant get my head around it. Basicly, if 8kg is needed to move an object horizontally at 0.25m/s what is the force?. (It's not just f=ma is it?). Thank you

OK, so lets say I'm cutting with a 6mm diameter cutter at a depth of 6mm with a 1kw router @ 25000rpm, the material is pine at a rate of 0.02m/s. John, this gives (correct me if I'm wrong) rate at which fresh surface exposed: (6e-3*6e-3)*0.02 = 7.2e-7 that multiplied my the mean 0.92 times 104 J m-2 gives 6.624e-3 (watts?) so, thats how much power is required to cut through said material?

valid point, lets say 1kw and 25000rpm

hi, I have this problem that I have no idea how to solve, I’m trying to do some calculations for a project, so, does anyone have any ideas what calculations you might use to work out what force is required to push a wood working router through material, I want to apply these calculations to many different routers so I suppose the wattage or rpm isn’t important? Any suggestions, thanks

hmm, so where does this leave us? sorry i should of said this is a homework problem. the pump spec is 500 rpm @ 12hp minimum, and i need to locate a motor that can power it which runs at 3000-4000rpm not costing more than $700. therefore i need to use a smaller motor and some hoe get the power required out of it, what do we think? thanks

hey, thanks alot for your help thats really useful, how come you'd use a worm gear? which would you put the worm gear on the compressor or the motor? would that be better than belts or chains? thanks

good, thanks, do you know any equations i can use to proove this? and at the gear ratio of 1:7 what size motor would get me to 12hp? thanks alot

hiya, i need some help for a project im working on, basicly i have a compressor pump that runs at 500rpm and @ 12 hp. now the problem is (this is a theoretical problem) i have to power it using a 3480rpm ac motor which has to be less than 10 hp (cost reasons). rough calculations show that a 20cm pulley on the compressor pump and a 3cm pulley on the motor will give me the correct speed reduction, but what do i do about power?. will the speed reduction increase torque giving me the power i need? if this is the case what is the minium sized motor i could use? what if i used gears, id be looking at a ratio of 1:0.15? hope thats clear, any websites or calculations that can help me with this would be amazing as im really baffled. thanks alot.