An Astronomer who made a list of 100 nebulae and galaxies that could
be mistaken for comets was Charles Messer's.
Charles Messier's was a very famous scientist in the field of Astronomy.
His research in appearance of Great comet filled spark to his passion
of Astronomy. On January 21, 1759 he put his thought of wrong
calculation of Delisle's and he described a faint glow resembling comet
had been seen earlier. Then after, he discovered great comet near
sword of Orion.
There are various tales of Charles Messiers which put him forward
towards his love of Astronomy.
Learn more about comet and Nebulae here:
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You may look at what group they are in
Group
1A=Group 1
2A = Group 2
3A = Group 13
4A= Group 14
5A=Group 15
6A=Group 16
7A=Group 17
The #A tells you how many valence electrons there are by the # before A. Such as Chlorine, which is in 7A, so therefore has 7 valence electrons.
Answer:
t = 2.5 hours
Explanation:
given,
speed of the bike for t time= 18 mi/h
final speed of the bike after t time = 12 mi/h
total distance, D = 69 miles
total time, T= 4.5 hour
time for which speed of the bike is 18 mi/h = ?
we know distance = speed x time
now,
18 x t + 12 (4.5 - t) = 69
6 t + 54 = 69
6 t = 15
t = 2.5 hours
The bike was at the speed of 18 mi/h for 2.5 hours.
Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height

To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height



So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point



Solving the quadratic equation



So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:


Since the projectile is going down the velocity at the instant it reaches the ground is:

Answer:
When light is passed through a true solution, the dissolved are too small to deflect light. suspensions may scatter light, but if the number of suspended particles is sufficiently large, the suspension may simply be opaque, and the light scattering would not occur.