Which of the following statements apply to electric charges ?
A. If a negatively charged rod is brought close to a positively charged object, the two objects will repel.
B. If a positively charge rod is brought close to positively charges object, the two objects will repel.
C. There are three types of charges.
D. Like charges attract, opposite charges repel.

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.

490 n

f=125n a=2.5m/s2