A foam ball of mass 0.150 g carries a charge of -2.00 nC. The ball is placed inside a uniform electric field, and is suspended against the force of gravity. What are the magnitude and direction of the electric field?

### 1 Answer | Add Yours

You need to evaluate the magnitude and direction of electric field, using Coulomb's force, such that:

`E = F/q`

Since the problem provides the mass of foam ball, you need to replace the product `m*g` for F, such that:

`E = (m*g)/q => E = (0.150*10^(-3)*9.8)/(-2*10^(-9))`

`E = -0.735*10^6N/C`

**Hence, E needs to point vertically downward because `q = -2*10^(-9)<0` and its magnitude is of **`E = 0.735*10^6N/C.`

### Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes