Answer:
108 extended days
Explanation:
Regular school hours a day = 6 hr
No. of school days to make up by extending the regular hours = 3 days
Amount of time added to the regular hours of school = 10 min
No. of extended school days to make up the 3 school days by following the above mentioned criteria be x.
Time of school hours in 3 days = 

are required to make up 3 days of school having 6 hours of regular timing with 10 minutes of add-on time each day.
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 .
W=mg
W=75(1.6)
W=120N
a. 120N
That's "displacement". It only depends on the beginning and ending locations, and doesn't care about the route between them.