Two boxes, connected by a cord, are pulled horizontally on a frictionless surface with an applied force of 40.0 N. Box A has a
mass of 10.0 kg; Box B has a mass of 12.0 kg.
(Hint: you have Fn & Fg for BOTH vertically, you have decide on the horizontal forces.)
a. Draw a free body diagram for box A.
b. Draw a free body diagram for box B.
c. Find the acceleration, a, of the two boxes.
d. Find the tension, FT, in the cord connecting boxes A and B

anchor = archer //

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.