Three charges in a line ( fast -please? (thanks))

[mujadeo]

three charges in a line (need help fast --please? (thanks))

Homework Statement

Two charges Qc and -Qc(Qc = 6 µC) are fixed on the x-axis at x = -8 cm andx = 8 cm, respectively. A third charge Qb = 2 µC is fixed at the origin. (attached .gif file shows the diagram)

A particle with charge q = 0.4 µC and mass m = 6 g is placed on the y-axis at y = 10 cm and released. There is no gravity.

Calculate the initial acceleration of the particle.

Homework Equations

I calculated the y component of the acceleration no prob. (asuby = 120m/s/s)

Im saying the x acceleration is zero, because all the acceleration is along the y-axis.
this is wrong for some reason?

Please help thanks!

The Attempt at a Solution

 

[Hootenanny]

Take note of the the signs of the two charges placed at (-8,0) and (8,0); one charge is Qc [i.e. positive] and the other is -Qc [i.e. negative]...

 

[m2003]

Hi there,

Thank you for reaching out for help. I understand that you are trying to calculate the initial acceleration of a particle placed on the y-axis at a certain distance from a fixed charge and released with no gravity. You have correctly calculated the y component of the acceleration, but you are unsure about the x component.

Firstly, let's review the concept of Coulomb's Law, which states that the force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. In this case, the force between the particle and the fixed charge at the origin would be:

F = k(qQb)/r^2

Where k is the Coulomb's constant, q is the charge of the particle, Qb is the charge of the fixed charge at the origin, and r is the distance between them. Note that this force is acting in the x direction, towards the origin.

Since the only force acting on the particle is in the x direction, the initial acceleration in the x direction would be:

a_x = F/m = k(qQb)/mr^2

Therefore, the initial acceleration in the x direction is not zero, but is dependent on the distance between the particle and the fixed charge at the origin. I would recommend plugging in the values given in the problem to calculate the initial acceleration in the x direction.

I hope this helps. Let me know if you have any further questions.

Best of luck with your studies!

Sincerely,