An object of mass 4 Kg starts at the origin in xy-plane with initial velocity vector, v(0) =< 1,1,1>. A force of magnitude 20 N acts directly upward from the xy-plane underneath the object, while gravitational force acts downward on the object. The magnitude of gravitational acceleration g = 10 m/s. Find, (i) the velocity v(t) and the position function r(t) of this object, (ii) the time it lands on ground, and (iii) the coordinates of its landing.

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.

graphing motion: mastery test

209be

what is the instantaneous acceleration of

the particle at point b?

0 meters/second?

10 meters/second?

12 meters/second?

velocity imetersisecond

15 meters/second?

20

time (seconds)

answer: 0 meters/second^2

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )