A900-kg car traveling east at 15.0 m/s collides with a 750-kg car traveling north at 20.0 m/s. the cars stick together. what is the speed of the wreckage just after the collision?

12.2 m/s

Explanation:

Initial momentum = final momentum

In the x direction:

(900 kg) (15.0 m/s) = (900 kg + 750 kg) vx

vx = 8.18 m/s

In the y direction:

(750 kg) (20.0 m/s) = (900 kg + 750 kg) vy

vy = 9.09

The magnitude of the velocity is therefore:

v = √(vx² + vy²)

v = 12.2 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.