Who Figured This Out? The American astronomer Edwin Hubble made the observations in 1925 and was the first to prove that the universe is expanding. He proved that there is a direct relationship between the speeds of distant galaxies and their distances from Earth. This is now known as Hubble's Law.
Answer:
Explanation:
Answer
The true fact is that C is what happens in outer space. Both rotations take 27.3 days.
A: The exact opposite is true. It does rotate about it's axis.
B: Again this is just plain false. Given the way we observe it, the moon must be rotating around the earth.
D. they don't. 27.3 hours and 24 hours are not the same.
Answer:
We have to show surface area 
,with few conditions that is by considering Force 
and Pressure 
to be respectively.
Explanation:
The atmospheric pressure is 
on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is 
.
Now to calculate surface area we can find it from 
and re-arranging it to.
So plugging the values,
Surface area 
Hence from the above calculations we can say that surface area is 
.
So the surface area of an average person can be said to have , using the concept of pressure and force.
Answer: 10.3m/s
Explanation:
In theory and for a constant velocity the physics expression states that:
Eq(1): distance = velocity times time <=> d = v*t for v=constant.
If we solve Eq (1) for the velocity (v) we obtain:
Eq(2): velocity = distance divided by time <=> v = d/t
Substituting the known values for t=15s and d=155m we get:
v = 155 / 15 <=> v = 10.3
Answer:potential difference is more or less like voltage. Using ohms, V=IR
Where V is Voltage
I is Current =0.4A
R is Resistance=20ohms
V=0.4*20
V=8V
Hence the potential difference will be 8V.
ii) V=0.4*30
V=12V
Explanation:
The voltage of potential difference is directly proportional to the current and the resistance. So if one increase or decrease, it will have impact on the other.
From the calculations, when the resistance increase, the voltage will increase to appreciate the change.
