Answer:
The heat causes the molecules on rubbing surfaces to move faster and have more energy.
The answer is pluto. just look it up
Answer:

So a=3.844 and b=5
Explanation:
Scientific notation requests to write a number using powers of ten as a factor accompanying a real number (a) between 1 and smaller than 10 that contains the digits to exactly represent the original number. So in this case, the number 384,400 can be written as:

with a=3.844, and "5" as the exponent of ten (so b=5)
Answer: The ray that passes through the focal point on the way to the lens will refract and travel parallel to the principal axis. ... All three rays should intersect at exactly the same point.
Explanation: Once these incident rays strike the lens, refract them according to the three rules of refraction for converging lenses.