Measuring things lets us understand the ?

To understand the behavior of the electric field at the surface of a conductor, and its relationship to surface charge on the conductor. a conductor is placed in an external electrostatic field. the external field is uniform before the conductor is placed within it. the conductor is completely isolated from any source of current or charge. part a: which of the following describes the electric field inside this conductor? it is in the same direction as the original external field. it is in the opposite direction from that of the original external field. it has a direction determined entirely by the charge on its surface. it is always zero. part b: the charge density inside the conductor is: 0non-zero; but uniformnon-zero; non-uniforminfinite part c: assume that at some point just outside the surface of the conductor, the electric field has magnitude e and is directed toward the surface of the conductor. what is the charge density η on the surface of the conductor at that point? express your answer in terms of e and ϵ0

Awave is propagating from left to right in a medium. the particles in the medium are also vibrating from left to right. what kind of wave does this describe? a. longitudinal wave b. transverse wave c. mechanical wave d. electromagnetic wave

The denser a substance, the more tightly packed it is. the table below shows the volume and mass of two different substances. comparison of substances substance volume (cm3) mass (g) r 22 10 s 55 25 which of the two substances is more tightly packed? object r is more tightly packed. object s is more tightly packed. both objects are packed equally tightly. this cannot be determined.