Finding resistance of single resistor

AI Thread Summary
To find the resistance of the second resistor in a parallel circuit where the total resistance is 6.0 ohms and one resistor is 10 ohms, the equation 1/RT = 1/R1 + 1/R2 is used. The correct calculation reveals that the second resistor's value is 15 ohms. Initially, trial and error was employed, leading to the same conclusion. The discussion emphasizes the importance of using algebraic methods for solving such problems. Ultimately, the solution was confirmed through proper application of the formula.
gungo
Messages
27
Reaction score
1

Homework Statement


Two resistors are connected in parallel. The total resistance of the combination is 6.0 ohms. If one of the resistors is 10 ohms, what is the value of the other?

Homework Equations


1/RT= 1/R1+1/R2

The Attempt at a Solution


I got 15 just by doing trial and error, and I'm pretty sure it's the right answer but how would you solve this using the equation?
 
Physics news on Phys.org
gungo said:
I got 15 just by doing trial and error, and I'm pretty sure it's the right answer but how would you solve this using the equation?
Via algebra, of course. What have you tried?
 
  • Like
Likes gungo
gneill said:
Via algebra, of course. What have you tried?
Whoops I forgot about using algebra. I got it, thanks!
 
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