Acomet entering the inner solar system from afar will )form a tail and some time later form a coma.2)form a coma and some time later form a tail3)always form a tail, but only sometimes form a coma

2)form a coma and some time later form a tail

Explanation:

Comets have two characteristic elements that make up their particular image: the comma and the tail. The comma is the diffuse cloud around the nucleus. Due to the composition of the comets (usually balls formed by no more than ice, frozen gases, dust and some rock fragments), when approaching the sun some of its components sublimate forming this ‘cloud’.

On the other hand is the tail or rather, the tails. Because a comet forms two different tails when the sun approaches: one of them is bluish and totally parallel to the direction of solar radiation, while the other is yellowish-white and forms an oblique path.

The first tail is formed by gaseous molecules of the coma, swept strongly and ionized by the solar wind (hence the bluish glow). These particles are aligned along the lines of the solar magnetic field, which has a more intense effect on them than the gravitational attraction itself. Generally, this is the most visible and spectacular tail.

But there is a second tail, formed by solid dust particles. These small fragments are also swept by the solar wind (which is obviously more intense the closer the comet approaches the sun). They are detached and form an oblique trajectory, due to their own inertia.

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

the maxium height is 34m/s