Electric potential ( with angle)

AI Thread Summary
The electric potential is given by V = 200 / √(x² + y²), and the electric field is derived by taking the negative gradient of V. At the point (2m, 1m), the electric field components are calculated as Ex = 35.78 and Ey = 17.89. The angle of the electric field is determined using arctan(Ey/Ex), resulting in an angle of 26.6 degrees. The confusion arises regarding the quadrant placement of the angle, with clarification that both components being positive places the angle in the first quadrant. Understanding the quadrant is crucial for accurately interpreting the direction of the electric field.
dmack15
Messages
7
Reaction score
0

Homework Statement


The electric potential of a region of space is V= 200 / sq root (x^2 + y^2), where x and y are in meters. What are the strength and direction of the electric field at (x,y) = (2m,1m)?

Homework Equations

The Attempt at a Solution


I took the negative derivative of V to find what the electric field would be. Then i substituted in (2,1)
200(2)(5)^-3/2 x + 200(5)^-3/2
=35.78x + 17.89 y

im having trouble figuring out where the angle should be. i do this a lot.

if i take the arctan or tan-1 of Ey/Ex

i get an angle of 26.6 degrees. Now is that 26.6 degrees ccw above the x-axis??
im having trouble figuring out where the final electric field will end up.
when i looked at the signs of x,y theyre both negative in the problem which means it would be quadrant 3.
even when i do 360-26.6 it ends in quadrant 4 which doesn't make sense

Please i don't need any help with the problem just with some help understanding the angle
 
Physics news on Phys.org
nevermind the x and y components are both positive so it falls in quadrant I.

thread closed
 

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

The sign of the change in potential
Replies
7
Views
463
Electric Potential Energy of Point Charge Systems
Replies
2
Views
940
Earthing of two parallel conducting plates
Replies
11
Views
1K
Calculating eletric potential using line integral of electric field
Replies
1
Views
2K
What is taken as datum level for the following absolute potentials?
Replies
2
Views
559
Finding electric potential of an infinite line charge at z axis
2
Replies
64
Views
4K
Electric field created by point charges
Replies
6
Views
815
Why are the electrostatic field lines normal to a charged conductor?
Replies
10
Views
1K
Calculate electric force using Coulomb's law (vector components are the struggle)
Replies
3
Views
1K
MIT OCW, 8.02 Electromagnetism: Potential for an Electric Dipole
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top