A real image twice the size of an object is formed by a concave mirror when the mirror and the object were shifted the mirror formed become four times the size of the object find the focal length of the mirror if the image were to be shift by 24cm Hint; in the first position of the object U = V/F -1 apply this to the second position​

The most important difference between a wedge and an inclined plane is a. their size b. their shape c. how they are used d. what they are made of

Which one of the following research methods can show cause and effect

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