Recent content by pls

yeah thats what i did. Just totally forgot that w=mg is actually f=ma,

yeah good, thought you meant it was accelerating upwards

can't use f=ma. Its moving at a constant speed so a = 0??

How'd everyone go? Wasn't too hard from memory but I'm pretty sure i didnt get the 2 marker about the standard model. Also with the last question, did anyone else talk about de Broglie using the pre-existing concept of 'waves acting as particles' to come up with the idea that 'particles can act...

Im pretty sure that when a motor spins it becomes a 'de facto' generator, since it is effectively a conductor moving in a magnetic field and hence there will be a current created which opposes the change in flux (i.e. a current in the opposite direction of supply current) so total current...

+1 to the silly error count. What about the motor with the mass attached. Im not sure i got that. Did you say f=w=mg which is 0.49 N or something like that? Then for the next bit find torque using t=fd (with f from the previous question and d= radius of the shaft or whatever that was) and equate...

I got rotational velocity = 73.4m/s. I equated f=ma with f=mv^2/r. You get v = √ (ar). Sub in a as 9.8 and r as the radius as 550.

I said torque decreases. Wouldn't back emf increase as the motor speeds up, hence decreasing current. Since t=nBIAcosø, torque would decrease?