Answer:
3. relatively high temperature, about 10,000 K, so that significant numbers of electrons are excited from the ground state, n = 1, to the first excited state, n = 2, but not too many of them have been ejected completely from the atoms
Explanation:
If hydrogen absorption lines are very strong in the visible spectrum of a particular star that means the population of electron in n = 2 is very high so on being exited they absorb radiation in Balmer series and give rise to absorption spectrum. The average temperature required to excite electron in hydrogen atom from n=1 to n = 2 is 10000K .
-- If the field were inclined to the surface, then it would have
some component parallel to the surface.
-- Then, since we're talking about a conductor, the charges
on the object would move in response to that component
of the field, until there was no longer any component of the
field trying to move them.
A constant velocity means the acceleration is zero.
This is an <em>inelastic </em>collision. The equation for an inelastic collision is: 
(110)(6) + (150)(-4) = (110 + 150)(vf)
660 - 600 = 260vf
60 = 260vf
vf = 0.2308 m/s
They will travel in the positive direction, right, and their combined velocity will be 0.2308 m/s.
Hope this helps!! :)
It's geography,
tropical climate