Three spheres, each with a negative chrge of 4.0x10^6C, are fixed at the vertices of an equilateral triangle whose sides are 0.20 m long. Calculate the magnitude and direction of the net electric force on each spehere.
i used this: (K)Cos30((4.0*10-6)*2)/(0.2*2)
and i get 3.1 every time...
I have answered this one twice as well
^ means exponent
times 2 for two spheres forcing third
http://www.jiskha.com/display.cgi?id=1293915742#1293915742.1293916579
thank you for responding:
i did:
(9.0*10^9)cos30((4.0*10^-6)^2)/(0.2^2)
using this i got 3.1. so then i need to double it because it's two spheres. right?
and sorry about the formula in the question. i confused my self with the "times" and "exponent".
cos 30 = 1/2
so 9*16 /4 and figure out decimal= 36 *10^(9-12+2)
= 3.6
oh sorry, cos 30 = .866
so
3.6*.866/.5
6.24
thank you. this was very helpful.
You are welcome.
Im working on this same question too and i cant figure out how you got the .5 when doing 3.6*.866/.5 ??? because i know the answer is correct, is it because the net force goes through the middle?
To calculate the magnitude and direction of the net electric force on each sphere, you can use the formula for the electric force between two charges. The formula is given by Coulomb's Law:
F = (k * |q1 * q2|) / r^2
Where:
- F is the magnitude of the electric force
- k is the Coulomb's constant (9 x 10^9 N m^2/C^2)
- q1 and q2 are the charges of the spheres
- r is the distance between the charges
In this case, we have a triangle with three spheres, and we want to find the net electric force on each sphere. Since the spheres are negative, they will repel each other.
To calculate the net electric force on each sphere, we need to consider the forces between each pair of spheres and their respective directions. The net electric force is the vector sum of these forces.
First, let's label the spheres as A, B, and C.
- The force on sphere A from sphere B will have a direction towards A since these are like charges (negative-negative).
- The force on sphere A from sphere C will also have a direction towards A since these are like charges.
Using Coulomb's Law, the magnitude of the force on sphere A from sphere B is:
F_AB = (k * |q1 * q2|) / r^2
= (9 x 10^9 N m^2/C^2) * (4.0 x 10^-6 C)^2 / (0.20 m)^2
Similarly, the magnitude of the force on sphere A from sphere C is also:
F_AC = (k * |q1 * q2|) / r^2
= (9 x 10^9 N m^2/C^2) * (4.0 x 10^-6 C)^2 / (0.20 m)^2
Since the forces are in opposite directions, we need to subtract them to find the net force on sphere A:
Net force on sphere A = F_AB - F_AC
Repeat this process for spheres B and C, considering the forces between them and the other spheres.
So, to get the correct value, calculate the forces individually and then subtract the appropriate forces to find the net force on each sphere.