Actually, they're not. There's a group of stars and constellations arranged
around the pole of the sky that's visible at any time of any dark, clear night,
all year around. And any star or constellation in the rest of the sky is visible
for roughly 11 out of every 12 months ... at SOME time of the night.
Constellations appear to change drastically from one season to the next,
and even from one month to the next, only if you do your stargazing around
the same time every night.
Why does the night sky change at various times of the year ? Here's how to
think about it:
The Earth spins once a day. You spin along with the Earth, and your clock is
built to follow the sun . "Noon" is the time when the sun is directly over your
head, and "Midnight" is the time when the sun is directly beneath your feet.
Let's say that you go out and look at the stars tonight at midnight, when you're
facing directly away from the sun.
In 6 months from now, when you and the Earth are halfway around on the other
side of the sun, where are those same stars ? Now they're straight in the
direction of the sun. So they're directly overhead at Noon, not at Midnight.
THAT's why stars and constellations appear to be in a different part of the sky,
at the same time of night on different dates.
Answer:
1995 and 2000 , 4 trillions
Explanation:
Radio waves are the longest
Answer:
a) F = 2250 Ib
b) F = 550 Ib
c) new max force ( F newmax ) = 2850 Ib
Explanation:
A) The force the wall of the elevator shaft exert on the motor if the elevator starts from rest and goes up
max capacity of elevator = 24000 Ibs
counterweight = 1000 Ibs
To calculate the force (F) :
we first calculate the Tension using this relationship
Counterweight (1000) - T = ( 1000 / g ) ( g/4 )
Hence T = 750 Ib
next determine F
750 + F - 2400 = 2400 / 4
hence F = 2250 Ib
B ) calculate Tension first
T - 1000 = ( 1000/g ) ( g/4)
T = 1250 Ib
F = 2400 -1250 - 2400/ 4
F = 550 Ib
C ) determine design limit
Max = 2400 * 1.2 = 2880 Ib
750 + new force - 2880 = 2880 / 4
new max force ( F newmax ) = 2850 Ib
Answer:
The correct option is;
The atoms and molecules of the liquid water are moving, while the atoms and molecules of the glass are not moving
Explanation:
Matter that exist in the liquid or gaseous state consist of molecules that move freely about in the entire containing medium for gas, while the molecules move freely in the portion of the container occupied by the fluid in the case of liquid fluids
However, the molecules of a solid are fixed within the current shape of the solid and are only free to vibrate within a fixed location and the allow the passage of subatomic particles such as electrons
As such, the glass cup being a solid, consists of molecules fixed in space, while the liquid water consists of molecules which can translate within the portion of the volume of the glass filled with the water.