Magnetic Force in a current carrying coil

AI Thread Summary
A rectangular loop falls into a magnetic field after descending 0.28 m, and the initial speed upon entering is calculated using v = √(2gd), resulting in 2.34 m/s. The discussion highlights that when the loop moves at constant speed, the gravitational force equals the magnetic force, leading to a calculation of gravitational force as F = mg = 245.25 N. The user seeks clarification on the equations needed for determining the magnetic force, magnetic field strength, and induced current, indicating that these depend on the results from the previous calculations. The focus remains on understanding the relationship between the forces acting on the loop as it enters the magnetic field. The thread emphasizes the importance of accurately applying physics principles to solve for the unknowns in the scenario.
nhartung
Messages
56
Reaction score
0

Homework Statement


A rectangular loop with length of l = 0.30 m and width w = 0.12 m and a mass of 25-grams falls (from rest) a distance of .28 m before entering a constant magnetic field that points out of the page. The internal resistance of the wire is 5.5 \Omega.

(i) What is the speed of the loop when it first enters BOut. (The magnetic field).

Here I think i can just use v = \sqrt{2gd} = 2.34 m/s. (correct me if this is an incorrect way of finding this.)

(ii) If, while the loops enters the magnetic field, it moves at a constant speed, then what is the magnetic force.

Here I'm stuck but I am thinking there is just some equation that I am missing but I've been searching my book and haven't found anything helpful.

(iii) What is the magnitude of the magnetic field BOut.

(iv) What is the magnitude of the induced current.

I'm thinking I can use I = \frac{LBsinø}{F} for this..

I just want to focus on (ii) right now because I think (iii) and (iv) depend on (ii)'s answer and hopefully are easy.
 
Last edited:
Physics news on Phys.org
Ok I think I've worked out (ii) Since the loop has constant velocity this means the acceleration is zero. This must mean the Force of Gravity and Magnetic Force are canceling each other (they are equal) which means F = mg = 245.25N. I still need some help on (iii) and (iv) though.
 
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