# Physics

posted by .

An oil droplet with a mass of 3.50 x 10^-15 kg accelerates downward at a rate of 2.50 m/s2 when it is between two horizontal charged plates that are 1.00 cm apart. Assuming that the excess charge on the droplet is negative and the top plate is positive, how many excess electrons does the droplet carry if the potential difference between the plates is 533 V?

Is this the equation I should be using..?

E = v/d

q E = m g

If I use the above eqs. I get the wrong answer =(

Plz help!! and thank you in advance! =)

• Physics -

qE = mg only if the droplet is stationary. Use the acceleration rate (a) to get

qE -mg = ma

You should be able to solve for q.

You do have the correct formula for E

• Physics -

I just figured that out but thank you very much! :)

## Similar Questions

1. ### physics

a.What electric potential difference exists across a 5.2 µF capacitor that has a charge of 2.1 10-3 C?
2. ### physics

In the Millikan oil drop experiment, an atomizer (a sprayer with a fine nozzle) is used to introduce many tiny droplets of oil between two oppositely charged parallel metal plates. Some of the droplets pick up one or more excess electrons. …
3. ### PHYSICS

In the early 1900s, Robert Millikan used small charged droplets of oil, suspended in an electric field, to make the first quantitative measurements of the electron’s charge. A 0.67-um-diameter droplet of oil, having a charge of +e, …
4. ### physics

Hi can someone please explain to me how to get the answers to the following questions. It would be greatly appreciated A pair of horizontal parallel plates are placed a small distance, 4.00 mm, apart in air. Each plate is rectangular …
5. ### Physics

A 0.7 um-diameter droplet of oil, having a charge of +e, is suspended in midair between two horizontal plates of a parallel-plate capacitor. The upward electric force on the droplet is exactly balanced by the downward force of gravity. …
6. ### physics

A small droplet of oil with mass of 1.84×10-15 kg is held suspended in a region of uniform electric field directed upward with a magnitude of 6625 N/C. Is the excess charge on the droplet positive or negative?
7. ### physics

8 1/2 HRS ON THIS MASTERING PHYSICS WOW n 1909, Robert Millikan was the first to find the charge of an electron in his now-famous oil-drop experiment. In that experiment tiny oil drops were sprayed into a uniform electric field between …
8. ### physics

1909, Robert Millikan was the first to find the charge of an electron in his now-famous oil-drop experiment. In that experiment tiny oil drops were sprayed into a uniform electric field between a horizontal pair of oppositely charged …
9. ### Physics

In a Milliken type experiment, two horizontal parallel plates are 1.0 cm apart. A sphere of mass 2.2 x 10^(-13) kg remains stationary when the potential difference between the plates is 350V with the upper plate is negative. How much …
10. ### physics

An oil-drop, that has a mass of 3.5 × 10-15 kg and an excess of 7 electrons, is located between horizontal parallel plates. The plates are separated by a distance of 2.5 cm and have and potential diffeDetermine the magnitude and direction …

More Similar Questions