An elevator ascends from the ground with uniform speed. a time tį later, a boy drops a marble through a hole in the floor. a time t2 after that (i. e. ti +t2 after start) the marble hits the ground. find an expression for the height of the elevator at time ti. (local gravity is g.) what checks can you make?

Explanation:

Let Ye be the position of the elevator, Ve be the velocity of the elevator and Ym the position of the marble. We know that:

  Since the marble hits the ground at T2, Ym=0m

Replacing Ye into the equation for Ym:

  Solving for Ve:

 Replcaing this value into Ye:

If we check units of Ye expression, they must be distance units.

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.