You drive 10 meters backwards and then 20 more meters backwards in 30 seconds. What is your average velocity?

Average velocity= 1 m/s

Explanation:

Step one:

given data

total distance covered =  10 meters backwards+  20 more meters backwards

toatal distance= 10+20= 30 meters

time taken = 20 seconds

Required

The average velocity

Step two:

the expression for the average velocity is

Average velocity= total distance/total time taken

Average velocity= 30/30

Average velocity= 1 m/s

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.