If the LED has an output power of .001 Watts = .001 Joule/second, how many photons are output by the LED per second?

Is there a point between a 10 nc charge and a 20 nc charge at which the electric field is zero?

Determine the moment of the force f about an axis extending between a and c. express the result as a cartesian vector. a is at the origin, c is at (4,3,0) and f = (4i + 12j -3k) lb coming out of b (4,3,-2).

Avector a⃗ has a length of 8.6 m and points in the negative x direction. find the x component of the vector −3.7a⃗ .