Answer:
Explanation:
An object is drop from a height, then it is in direction of gravity
g is +ve
When an object drop from a height, the initial velocity is 0,
U=0
Given that h=4.4×10^7m
V=?
g=9.81m/s^2
Then using equation of motion
V^2=U^2+2gh
V^2=0+2×9.81×4.4×10^7
V^2=86.33×10^7m/s
Take square root of both side
V=29381.63m/s
Now to km/s, divide by 1000
Since 1km=1000m
V=29.38km/s
The answer is to u question is: C
Answer:
28 moles of X.
Explanation:
Let's consider the complete combustion of ethanol.
C₂H₆O(l) + 3 O₂(g) ⇒ 2 CO₂(g) + 3 H₂O(l)
When 1 mole of ethanol burns it releases 1370 kJ, that is, the enthalpy of combustion is -1370 kJ/mol. If the energy released by one mole of etanol were used to syntesize the compound X, it would take 45.9 kJ to form 1 mole of X, that is, the enthalpy of formation is -49.5 kJ/mol. Then,

Answer:
When you have two materials with the same index of refraction, it means that if they are touched by a ray of light it won't have a chance, and its form would prevail.
Explanation:
The reason behind this is that in the first place. When light passes through an object of certain refraction it is modified from its natural state, allowing it to change in color to the human eye or many other effects in other perceptive elements. However, when the same light passes through two objects with the same refraction due to their physical characteristics, it doesn't change because once it comes out of the first one it will suffer the same effect from the last one. For it to change the refraction would have to be higher or lower. Then it would be modified. The reason is because the dimensions are not modified. Because at some point the ray of light has to come out of the first one to enter the second one.
noting or pertaining to a speed less than that of sound in air at the same height above sea level.