Solving for Electric Field Strength & Direction of Charged Sphere

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SUMMARY

The discussion focuses on calculating the electric field strength required to balance the weight of a 1.0g plastic sphere charged to -3nC. The electric field (E) is derived using the formula E = mg/q, resulting in a value of 3 x 106 N/C. The direction of the electric field is determined to be opposite to the gravitational force, as the electric force must counteract the weight of the sphere for it to remain in equilibrium.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Familiarity with electric charge and electric fields
  • Knowledge of basic physics equations, specifically E = F/q
  • Concept of force balance in static equilibrium
NEXT STEPS
  • Study the relationship between electric fields and forces on charged objects
  • Explore the concept of electric field direction and its implications
  • Learn about the effects of different charge types on electric field strength
  • Investigate applications of electric fields in real-world scenarios, such as in capacitors
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Students studying physics, particularly those focusing on electromagnetism, as well as educators looking for practical examples of electric field calculations.

Lydia22
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Homework Statement



What are the strength and direction of an electric field that will balance the weight of a 1.0g plastic sphere that has been charged t0 -3nC ?


Homework Equations


E= F/q



The Attempt at a Solution



Newton's laws on the charged sphere

ƩFnet(y) = F -mg=0
F=mg\
F=qE
E = mg/q
=[(0.003kg)(9.8m/s^2)]/(3.0x10^-9C)
=3x10^6 N/c
how do i conclude on the direction?
 
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Hi Lydia22! :smile:

You have already used what the direction must be.
So you only have to make your conclusion explicit.

In your first line you have ƩFnet(y) = F -mg=0, which is the condition for the sphere to be in balance.
This implies that the electric force is equal and opposite to the force of gravity.
Since q is positive, that also holds true for the electric field.
 

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