Force of weight of the suspended ball

AI Thread Summary
The discussion centers on calculating the forces acting on two charged pith balls, one suspended and one brought close to it. The weight of the suspended ball can be calculated using the formula W=mg, but the problem also involves understanding the forces due to gravity and electrostatic repulsion. Participants emphasize that the gravitational force has components that need to be considered, specifically mgcos(30) and mgsin(30), which relate to the angle formed by the suspended ball. Balancing the gravitational force with the repulsive force will help determine the net charge on each ball. The conversation highlights the importance of analyzing forces in terms of torque and components to solve the problem effectively.
Biya
Messages
4
Reaction score
0
i kinda need help. okay I am posting my question:
Two pith balls have a mass of 1.0g and have equal charges. One pith ball is suspended by an insulating thread. The other is attached to a static insulator and is brought close to the suspended ball so that they are 5 cm apart when repulsion occurs. After repulsion, they come to rest such that both are at the same height above ground. The suspended ball is now hanging with the thread forming a 30 degree angle with respect to its former position. Calculate the following:
1-Force of weight of the suspended ball.
2-The force of repulsion between the two.
3-The net charge on each.
I have no idea how to find out the force of repulsion and the net charge. We can find the weight my using the W=mg formula. So I'm confused with that. I need help . Thank God i found this cool forum
 
Last edited by a moderator:
Physics news on Phys.org
The weight factor in the other parts isn't a simple W = mg problem. Try considering the force due to gravity as a torque and the repulsion from the other ball as a countertorque. I hope this gets you started.
 
vsage said:
The weight factor in the other parts isn't a simple W = mg problem. Try considering the force due to gravity as a torque and the repulsion from the other ball as a countertorque. I hope this gets you started.
I didn't get it do you mean gravitational force by force due to gravity?
i didnt get it :rolleyes: :rolleyes: :frown:
 
The force due to the Earth's gravity has components is what I'm referring to. These components can be broken up into components parallel and perpendicular to the line between the centers of the two balls. (namely mgcos(30) and mgsin(30)) If you set the force of gravity acting to push one ball toward the other and balance it with the repulsive force of the charge on the two balls you should find your answer. Clearer?
 
vsage said:
The force due to the Earth's gravity has components is what I'm referring to. These components can be broken up into components parallel and perpendicular to the line between the centers of the two balls. (namely mgcos(30) and mgsin(30)) If you set the force of gravity acting to push one ball toward the other and balance it with the repulsive force of the charge on the two balls you should find your answer. Clearer?

Ys yes yes yes thank u thank u thank thanku :biggrin: :biggrin: :biggrin: :biggrin: :smile: :smile: :smile: :biggrin:
 
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 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
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