
#1
Feb913, 12:11 PM

P: 5

1. The problem statement, all variables and given/known data
Two small insulating spherical bead are placed on a taut(insulating, isolated) string which has a knot at its lower end. The string is stretched at an angle of 60degress to the horizontal. The beads can move frictionlessly on the string. The beads are given identical positive charges (which are distributed evenly over the tiny volumes of the beads). The lower bead rests against the knot. The other bead comes to rest 5cm away from the knot on the string. The mass of each bead is 0.1g. What is the charge on the beads? 2. Relevant equations 3. The attempt at a solution Would I use work? Or something else? Not quite sure Just an idea of even what equation to start with would be nice 



#2
Feb913, 12:15 PM

HW Helper
Thanks ∞
PF Gold
P: 4,482

Think about how it is possible that the bead can remain at rest. What forces act on the bead?




#3
Feb913, 01:04 PM

P: 5

well there would be the force that pushes the two beads apart, and gravity?




#4
Feb913, 01:04 PM

P: 5

Finding the charge on two beads? 



#5
Feb913, 01:08 PM

HW Helper
Thanks ∞
PF Gold
P: 4,482

What is the condition that must be met by these 3 forces for the bead to remain at rest? 



#6
Feb913, 01:13 PM

P: 5





#7
Feb913, 01:18 PM

HW Helper
Thanks ∞
PF Gold
P: 4,482





#8
Feb913, 01:46 PM

P: 5





#9
Feb913, 08:49 PM

HW Helper
Thanks ∞
PF Gold
P: 4,482

Good work. Welcome to PF!



Register to reply 
Related Discussions  
beads on a string on a peg  Introductory Physics Homework  18  
Finding total charge from volume charge density  Introductory Physics Homework  2  
Electrostatics  finding the total charge of a sphere with varying charge density  Introductory Physics Homework  1  
Charged Beads  Advanced Physics Homework  1  
Beads  Introductory Physics Homework  4 