A uniform electric field 31.4i + 47.7j N/C intersects a surface of area 1.00m^2. What is the flux through this area if the surface lies in the yz-plane?

Question

anonymous · Answer

im just confused with the angle do i use sin 90 why?

anonymous · Answer

when do i know when to use cos or sin?

anonymous · Answer

equation for flux is= (E)(A)cos(theta)

anonymous · Answer

btw i already know the solution to the question just looking for an explanation

lastdaywork · Answer

Always use cos; no need to swap b/w trigonometric ratios.

Area vector would be perpendicular to yz plain; i.e. parallel to x-axis

lastdaywork · Answer

If you are given E (or A) in vector form; consider using the dot product.

anonymous · Answer

yea yea the x component by the area will give me the answer so do i just ignore cos(theta)? :S

lastdaywork · Answer

There are two formulas for dot product; you can always use one and ignore the other :)

anonymous · Answer

ohh well that was easy enough aha thanku :)

lastdaywork · Answer

Welcome :)