How to find one value in terms of other variables?

AI Thread Summary
To find q in terms of f and p, the equation 1/p + 1/q = 1/f can be manipulated by isolating q. The correct steps lead to the equation 1/q = (1/f) - (1/p), which simplifies to 1/q = (p-f)/(pf). Ultimately, this results in q = pf/(p-f). The calculations and final expression for q are confirmed to be correct.
Eddie10
Messages
27
Reaction score
1

Homework Statement



I need to find q in terms of f and p.

Homework Equations


I am dealing with this equation at the moment:
1/p + 1/q = 1/f.

The Attempt at a Solution


I think I should isolate the q, so that I have the variables p and f on one side of the equals sign, and q on the other side of the equals sign.

Am I correct in thinking this?
 
Physics news on Phys.org
Yes.
 
My results:

1/q =(1/f) - (1/p)

1/q= (p-f)/(pf)

q= pf/(p-f)

Are they correct?
 
Yes.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top