Question

Electrodisc, the sport of the future, has players skating across the field on hover shoes pushing around metallic discs. When discs collide players get points based on the amount of charge exchanged. The players today are playing the popular three disc variant of Electrodisc where each disc has the following charges: qA = 2q, qB = −5q, and qC = 0q (no net charge). In the first quarter of the game the opposing team is able to touch disc A and B together then separate them. Then the home team scores by touching disc C to disc A and then separates them. Finally, the opposing team scores again by touching disc C to disc B and then separates them. (Give your answers in terms of q.)

Required:
a. What is the final charge of object C?
b. Before the objects touch, what is their total charge?
c. After the objects touch, what is their total charge?

Answer 1

The final charge of object C is -1.125q after touching and separating from the other discs. The total charge of all three discs before they touch is -3q, which remains conserved after they separate.

Step-by-step explanation:

Understanding Charge Distribution in Electrodisc

When the three discs are involved in a game of Electrodisc, and they touch each other, they transfer charge according to the principles of charge distribution. Let's analyze the charge transfer step by step as per the scenario described:

1. Disc A (2q) touches Disc B (-5q): The total charge is (2q - 5q) = -3q. Since both discs are identical, they will share the charge equally becoming -1.5q each after separation.
2. Disc C (0q) touches Disc A (-1.5q): Consequently, the total charge is -1.5q. Shared equally, each disc ends up with -0.75q.
3. Disc C (-0.75q) touches Disc B (-1.5q): The combined charge is (-0.75q - 1.5q) = -2.25q. When they separate, each has a charge of -1.125q.

a. The final charge of object C is -1.125q.

b. Before the objects touch, their total charge is the sum of their individual charges: (2q) + (-5q) + (0q) = -3q.

c. After the objects touch and then separate, the total charge remains conserved. It is still -3q.

Answer 2

a) -1.125q

b) -3q

c) -3q

Step-by-step explanation:

The discs are A, B, and C

Their charges are;

A = 2q

B = -5q

C = 0q

In the first quarter of the game the opposing team is able to touch disc A and B together then separate them. This leaves a net charge of

`(2q + (-5q))/(2)` = -1.5q on each of the discs A and B.

Then the home team scores by touching disc C to disc A and then separates them. This leaves a charge of

`(-1.5q + 0q)/(2)` = -0.75q on the discs C and A.

Finally, the opposing team scores again by touching disc C to disc B and then separates them. This leaves a charge of

`(-0.75q + (-1.5q))/(2)` = -1.125q on the discs C and B

a) the final charge of object C = -1.125q

b) Before the objects touch, their total charge = 2q + (-5q) + 0q = -3q

c) After the objects touch, their total charge = (-0.75q) + (-1.125q) + (-1.125q) = -3q