A double-concave lens has equal radii of curvature of 15.1 cm. An object placed 14.2cm from the lens forms a virtual image 5.29cm from the lens. What is the index of refraction of the lens material?
a) 1.77
b) 1.98
c) 1.82
d) 1.90 <--- Correct answer, but I do not know how to solve for it.
e) 1.04

The respiratory system removes oxygen and water from the body. select the best answer from the choices provided t f

How do the kidneys affect homeostasis

Intro: a solid ball of radius rb has a uniform charge density ρ. part a: what is the magnitude of the electric field e(r) at a distance r> rb from the center of the ball? express your answer in terms of ρ, rb, r, and ϵ0. part b: what is the magnitude of the electric field e(r) at a distance r express your answer in terms of ρ, rb, r, and ϵ0. part c: let e(r) represent the electric field due to the charged ball throughout all of space. which of the following statements about the electric field are true? check all that apply. e(0) = 0 e(rb)=0 limr→∞e(r)=0 the maximum electric field occurs when r=0 the maximum electric field occurs when r=rb the maximum electric field occurs as r→∞.