Suppose you wanted to be able to see astronauts on the moon. what is the smallest diameter of the objective lens required to resolve a 0.67 m object on the moon? assme the wavelength of the light is near the middle of the visible spectrum: 550 nm yellow light.

r = distance of moon from earth = 3.84 x 10⁸ m

R = size of the object on moon = 0.67 m

D = diameter of the lens = ?

= wavelength of light = 550 x 10⁻⁹ m

Using the equation for Rayleigh criterion

R/r = 1.22 /D

inserting the values

0.67/(3.84 x 10⁸) = 1.22 (550 x 10⁻⁹) /D

D = 384.6 m

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

emily ruth's annual premium is $1058.50

step-by-step explanation:

emily ruth is a female of 27 years age purchasing 20 year endowment insurance with face value $25000.

from the given table,

for females, the age of a male 3 years younger should be used.

so, we have to check for 24 year male for 20 year endowment.

it is 42.34 for every $1000 face value.

for a face value of $25000,

it is 25 * 42.34 = $1058.50

∴ emily ruth's annual premium is $1058.50