Electric field direction and hovering charged object

In this scenario, the object has a negative charge, so the electric field must be directed downwards in order for the object to remain suspended. This is because the electric field and the gravitational force are in opposite directions, and they must balance each other out for the object to remain motionless. Therefore, in summary, the magnitude of the electric field is determined by the mass and charge of the object, and the direction of the electric field is determined by the sign of the charge.
  • #1
illidari
47
0

Homework Statement



A small object of mass 3.64 g and charge -18.1 µC is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. What are the magnitude and direction of the electric field?


Homework Equations



E=F/q

The Attempt at a Solution



I solved for the magnitude and was fine with that but was wondering why the electric field direction would be downwards?

Why couldn't it be upwards?

E = m*g / -q = -#

My logic was that a - electric field upwards would make the charged object hover since - and - repel.

I guess if it was going downwards the same effect would still occur, but I don't understand (if this is even right...) how to determine if up or down.
Am i completely off track on how to think about this?
 
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  • #2
The direction of the force depends on the electric field and the sign of the charge. Positive charges experience a force in the direction of the electric field, and negative charges experience a force in the opposite direction.
 

Related to Electric field direction and hovering charged object

1. What is an electric field?

An electric field is a region around a charged object where the force of electricity is felt. It is created by the presence of electric charges and can exert a force on other charged objects within its range.

2. How is the direction of an electric field determined?

The direction of an electric field is determined by the direction of the force that a positive test charge would experience if placed in that field. The field lines always point away from positive charges and towards negative charges.

3. How does a charged object hover in an electric field?

A charged object can hover in an electric field when the force of the electric field is equal and opposite to the force of gravity. This is known as electrostatic levitation and is often used in experiments with charged particles.

4. Can the direction of an electric field change?

Yes, the direction of an electric field can change depending on the location and charge of the objects creating the field. The field lines always point towards the direction of the force, so if the charge or position of the objects change, the direction of the field will also change.

5. How does the strength of an electric field affect a hovering charged object?

The strength of an electric field directly affects the force experienced by a hovering charged object. The stronger the electric field, the stronger the force, and the more stable the object will be in its hover. If the electric field is too weak, the object may not be able to overcome the force of gravity and will not be able to hover.

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