What electric field E⃗ strength will cause the bead to hang suspended in the air?

Question

A 0.170 g glass bead is charged by the removal of 1.20 x10 ^10 electrons.

What is the direction of the electric field EE⃗  at which the bead will hang suspended in the air?

E ⃗ at which the bead will hang suspended in the air?

Answer 1

The mass of the glass bead is .

The glass bead is charged by removal of electrons.

The electric field is that of a positive charge on the glass bead.

The charge is assumed to be a point charge.

The glass bead hangs suspended in the air when the net force acting on the bead is zero.

The two forces that act on the bead are electric force and the weight.

Because the bead is positively charged , the electric field must be pointed upwards to cause an downward force, which will balance the weight.

.

The electric field is .

.

.

The direction of the electric field is away from the bead.

Therefore, the direction of the electric field is upwards.