An aircraft, traveling northward, lands on a runway with a speed of 79 m/s. Once it touches down, it slows to 6.0 m/s over 785 m of runway. What is the average acceleration (magnitude and direction) of the plane during landing (in m/s2)? Take the positive direction to be northward.

, South

Explanation:

We are given that

Initial speed of aircraft,u=79 m/s

Final speed of aircraft,v=6 m/s

Distance,s=785 m

Substitute the values

Where negative sign indicates that the direction of acceleration is opposite to direction of motion.

Therefore, the direction of acceleration is south.

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.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it