How Does Electric Field Magnitude Make a Charged Ball Float?

[arod2812]

Homework Statement

A tiny ball (mass = 0.014 kg) carries a charge of -17 C. What is the electric field magnitude that would cause the ball to float above the ground?

Homework Equations

what equation should I use? I am not sure how to even start this problem.

The Attempt at a Solution

Would using E = q/ ((E0 * A) be a good start?

 

[blochwave]

Not even that complicated, there's a ball with a mass m

So there's a gravitational force acting downward on the ball that you should be able to find out

You need to counter this gravitational force with another force caused by an electric field

If you know the charge, you just need to find the electric field. What's the relationship between charge, electric field, and actual force?

 

[arod2812]

I think I got it... So i should use the E=F/q. And the force is the mass*acceleration which is gravity because it is directed downward.

Thanks.

 

[blochwave]

Right

so Fgrav=Felectric

and Felectric=E*q