Calculate the magnitude and direction of the net electric force

In summary, the conversation involved calculating the net electric force on three point charges with given magnitudes and distances. The equations and conversions necessary for the solution were discussed and the final answer of 47.8 to the left was determined.
  • #1
crybllrd
120
0

Homework Statement



Three point charges lie along a straight line as shown in the figure below, where q1 = 6.60 µC, q2 = 1.41 µC, and q3 = -1.9 µC. The separation distances are d1 = 3.00 cm and d2 = 2.00 cm. Calculate the magnitude and direction of the net electric force on each of the charges.

2u91oco.gif


I need to state the magnitudes and directions of all 3 charges.

Homework Equations



[itex]F_{e}=k_{e}\frac{|q_{1}||q_{2}|}{r^{2}}[/itex]

The Attempt at a Solution




I have to convert the values to be able to properly use the equations.
q1=6.60e-9 C
q2=1.41e-9 C
q3=-1.9e-9 C
d1=.03 m
d2=.02 m
k=8.9876e9

I think I will only need help with the first part, I then should be able to do the rest on my own.
between q1 and q2:
[itex]F_{e}=(8.9876e9)\frac{|6.60e-9||1.41e-9|}{.03^{2}}=9.29e-5[/itex]to the left

between q1 and q3:
[itex]F_{e}=(8.9876e9)\frac{|6.60e-9||-1.9e-9|}{.05^{2}}=4.51e-5[/itex] to the right

I will now subtract the answers: (9.29e-5)-(4.51e-5)=4.78e-5
The force to the left is greater than the force to the right, so it will move to the left.

When I put this answer it says "Your response differs significantly from the correct answer."
The to the left part is obviously right.

What did I do wrong here?
 
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  • #2
crybllrd said:
I have to convert the values to be able to properly use the equations.
q1=6.60e-9 C
q2=1.41e-9 C
q3=-1.9e-9 C
I haven't looked at the rest of your work, but these are not quite right. Realize that μ means 10-6, not 10-9.
 
  • #3
Thanks a lot, I did have the conversions wrong.
I re worked it out and came up with the correct answer of 47.8 to the left.
Thanks again.
 

Related to Calculate the magnitude and direction of the net electric force

1. What is the formula for calculating the net electric force?

The formula for calculating the net electric force is F = k * (q1 * q2)/r^2, where k is the Coulomb's constant, q1 and q2 are the charges of the two objects, and r is the distance between them.

2. How do you determine the direction of the net electric force?

The direction of the net electric force is determined by the direction of the individual electric forces acting on the objects. If the charges are of the same sign, the forces will repel each other and the net force will be in the direction away from the other object. If the charges are of opposite signs, the forces will attract each other and the net force will be in the direction towards the other object.

3. What units are used for the net electric force?

The net electric force is typically measured in Newtons (N), which is the unit for force in the SI system. In some cases, it may also be measured in dynes (dyne) in the CGS system.

4. Can the net electric force be negative?

Yes, the net electric force can be negative if the charges of the objects have opposite signs. In this case, the force will be attractive and have a negative direction.

5. Is the net electric force always the same as the electric field?

No, the net electric force is not always the same as the electric field. The electric field is a vector quantity that represents the force per unit charge at a given point, whereas the net electric force is the actual force between two charged objects. The electric field can change depending on the location and magnitude of the charges, while the net electric force remains constant as long as the charges and distance between them do not change.

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