If you write down the formula for friction, you will get an answer.
Ff = u * N Where N is a push down force that an object experiences.
u (mu) is a constant and has no units
It may not be accelerating and still experience friction. A is not correct.
Color and Density will not affect the frictional force. B is not so.
Buoyant forces are a different thing altogether. Generally friction has nothing to do with them. C is incorrect.
The last one is your answer. Technically mg should be the answer and not mass, but the second part is correct.
The lithosphere because it includes the outer region of the earth including the crust and outer mantle
Sewage. If thats not it, then I need to see your choices. :)
Which of the following statements is TRUE?
A. Pollen, cat hair, and mold could trigger an asthma attack for some people.
I am fairly certain that this one is correct. Hope this helps! :)
Answer:
The problem occurs with all spherical mirrors.
Spherical mirrors are practical up to about inches in diameter.
Reflecting telescopes use spherical mirrors for apertures up to about 4 ".
Larger aperture telescopes use parabolic mirrors to obtain sharp focus.