The wooden block is removed from the water bath and placed in an unknown liquid. in this liquid, only one-third of the wooden block is submerged. is the unknown liquid more or less dense than water?

1.5 g/cm^3

Explanation:

In the question i am assuming that wooden block of weight W floats with exactly one-half of its volume below the waterline.

Let ρ_{liquid} be the density of the unknown liquid , V= volume submerged

g= acceleration due to gravity

then

weight of block =

when the block is in water

Also,

weight of block =

dividing eq 1 by eq 2 we get

⇒

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

snell's law

refractve index = sin incidence / sin refraction