How Do You Calculate the Electric Field at Point P with Two Charges?

AI Thread Summary
To calculate the electric field at point P due to two charges, use the formula E = (8.99e9 * q) / r^2, where r is the distance from the charge. The electric fields from both charges must be considered as vectors, adding them at the specified angle of 41 degrees. The participant initially attempted to calculate the resultant field by multiplying the electric field by the sine of the angle, but this approach was incorrect. It's essential to resolve the electric fields into their components and then sum these components to find the total electric field at point P. Proper vector addition will yield the correct resultant electric field direction and magnitude.
kpw0629
Messages
1
Reaction score
0

Homework Statement



Your Open QuestionShow me another »
Electric field help, please?
Find the electric field at P in the figure shown below. (Take r = 1.5 m and θ = 41°. Measure the angle counterclockwise from the positive x-axis.)
http://i834.photobucket.com/albums/zz264/kpw0629/1-1.gif


Homework Equations



E=(8.99e9*q)/r^2

The Attempt at a Solution


Ive been doing (8.99e9*q)/r^2=a and then multiplying a by sin of 41 degrees=b. Then, multiplying b by 2=.58 because theyre the same force and you add them together, but that's not right and I don't know what to do differently. I feel like the angle would also be 41 (or 319) because they're even forces but I don't know.
Thanks for any help.
(8.99e9*1/9e-9)/1.5^2=.4439*sin41=.29*2=.58
 
Last edited:
Physics news on Phys.org
sin(a)=opposite side/hypotenuse

cos(a)= close side/hypotenuse
which one should be used here?

The 2 charges create the same electric field so the two add up but at an angle. Consider the 2 fields as forces acting on a point and see how they add up.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Electric field created by point charges
Replies
6
Views
815
Find the Electric field at point p
Replies
2
Views
2K
Find the magnitude of the electric field at point P
Replies
5
Views
2K
Why is electric field at the center of a charged disk not zero?
Replies
4
Views
3K
Electric field strength at a point due to 3 charges
Replies
3
Views
2K
How Is the Electric Field Calculated for a Point Outside a Charged Ring?
Replies
11
Views
3K
Find the electric field between 2 finite discs
Replies
16
Views
1K
Find the electric field at a point away from two charged rods
Replies
11
Views
4K
Electric field external to Conducting Hollow Sphere with charge inside
Replies
23
Views
3K
Electric field at a point within a charged circular ring
2
Replies
68
Views
7K

Hot Threads

Recent Insights

Back
Top