Apaleontologist measures the ratio of carbon-14 to carbon-12 in a fossil skull found at a site. what technique is he using and for what purpose?
a. using alpha emission to determine the structure of the skull
b. using radioactive decay to determine the structure of the skull
c. using gamma emissions to date the skull
d. using radioactive decay to date the skull

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.