Current Electricity: Force Calcs & Plate Impact

[Kylah]

[SOLVED] Current Electricity

1. A positively charged particle enters an evacuated region between two parallel plates with an initial horizontal velocity of 29.6 m/s, as shown in the following diagram. The particle has a mass of 35.6 mg and a charge of +8.40 nC.
i168.photobucket.com/albums/u173/pleasetheworld/physicss.jpg

A) Will either the force of gravity or the force of air resistance play a role in the motion on this particle? Support your answer.
I assumed the force of gravity would act downwards on the particle. I'm not sure though. Haha.

B) Do the necessary force calculations to determine which plate the particle will strike. Begin your solultion with a labelled diagram.
So I did the diagram, and this is what I've done so far with the calculations:

Fnet= Fe + Fg
Fnet= |Fe|, up + |Fg|, down
Fnet= +|Fe| + -|Fg|
ma= q|E| - mg
a = (qE - mg)/m

I assume all I need to do is plug in values, but, I have a rather stupid question, what does nC mean? Does it just mean I need to change the +8.40 value to 8.40 x 10^-9?

Do I appear to have the write idea with the calculations?

 

[Poop-Loops]

1) Why do you think gravity would effect the particle? Saying "I'm not sure" is ok, but for me to help you I have to know why you think so.

2) nC is nano-Coulomb, so you are right, just multiply it by 10^-9.

3) Your math looks correct.

 

[Moetasim]

A) In this scenario, neither the force of gravity nor the force of air resistance will play a significant role in the motion of the particle. This is because the particle is moving in a vacuum, so there is no air resistance, and the force of gravity is negligible due to the small mass of the particle.

B) Your calculations so far are correct. And yes, nC stands for nanocoulomb, which is equal to 10^-9 coulombs. So you are correct in assuming that the charge value should be multiplied by 10^-9.

To determine which plate the particle will strike, we need to look at the direction of the electric field between the plates. Since the particle has a positive charge, it will experience a force in the direction of the electric field. In this case, the electric field is directed from the positive plate to the negative plate.

Plugging in the values for the force equation, we get:
a = (8.40 x 10^-9 C)(0.04 N/C) - (35.6 x 10^-6 kg)(9.8 m/s^2) / (35.6 x 10^-6 kg)
a = 1.344 x 10^4 m/s^2

Since the acceleration is positive, the particle will accelerate towards the positive plate. So the particle will strike the positive plate.

In conclusion, in this scenario, the force of the electric field between the plates is the dominant force, causing the particle to accelerate towards the positive plate. Additional factors such as air resistance and gravity are negligible in comparison.