Potential difference of falling charge particle

AI Thread Summary
The discussion centers on calculating the potential difference (Vb - Va) for a charged particle moving in a gravitational field. The particle, with a mass of 7*10e-5 kg and a charge of 1e-6 C, experiences a decrease in kinetic energy of 5.3 mJ over a distance of 3 m. Participants note that the positive charge moves in the same direction as gravity, indicating an opposing electric field. The conservation of energy principle is referenced, suggesting that work done by the electric field can be equated to changes in kinetic and gravitational potential energy. The thread seeks clarification on how to effectively apply these concepts to find the potential difference.
phymateng
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Homework Statement


A particle of mass 7*10e-5 kg and charge 1e-6 C from point A to point B a distance of 3 m in the Earth's gravitational field. The kinetic energy of the particle decreases by 5.3mJ during this movement. The acceleration of gravity is 9.8 m/s^2. What is the potential difference Vb-Va?


Homework Equations



I don't know how to get the Electric Field. I know that its a positive charge going in the same direction as the gravitational field. Since the problem says that the final kinetic energy is decreasing, then I know the velocity is decreasing and giving me a hint that there is an electric field counteracting the gravitational field. I could use the sum of all forces to equate both the fields, but that is only when the charge would stop. Do I have the right Idea?

The Attempt at a Solution



Tried to do the sum of all forces and the conservation of energy.
 
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W = q*ΔV

So you have Δ½mv² and Δmgh.

So if there was some work involved ... any ideas?
 

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