Answer:
<em>The comoving distance and the proper distance scale</em>
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Explanation:
The comoving distance scale removes the effects of the expansion of the universe, which leaves us with a distance that does not change in time due to the expansion of space (since space is constantly expanding). The comoving distance and proper distance are defined to be equal at the present time; therefore, the ratio of proper distance to comoving distance now is 1. The scale factor is sometimes not equal to 1. The distance between masses in the universe may change due to other, local factors like the motion of a galaxy within a cluster. Finally, we note that the expansion of the Universe results in the proper distance changing, but the comoving distance is unchanged by an expanding universe.
Answer:
Mass of the aluminium chunk = 278.51 g
Explanation:
For an isolated system as given the energy lost and gains in the system will be zero therefore sum of all transfer of energy will be zero,as the temperature will also remain same
A specific heat formula is given as
Energy Change = Mass of liquid x Specific Heat Capacity x Change in temperature
Q = m×c×ΔT
Heat gain by aluminium + heat lost by copper = 0 (1)
For Aluminium:
Q = 
Q = m x 17.94 joule
For Copper:

Q= 4996.53 Joule
from eq 1
m x 17.94 = 4996.53

Mass of the aluminium chunk = 278.51 g
Answer:
C
Explanation:
becauase i just tooke the test
Answer:
b. Hill top
Explanation:
On a topographic map, the closed circles are meant to represent a hill. So if the contour lines are creating a group of concentric closed loops then it must be an indication of a hill.
Answer:
The average force exerted on the man by the ground therefore is 153.319.53 N
Explanation:
Given the following information
Mass of man, m = 75 kg
height of fall, h = 0.48 cm
velocity just before landing, v = 4.43 m/s
We therefore have
The work required to break the fall is equal to the kinetic energy of motion, just before touching the ground
Work done = Energy to absorb Kinetic Energy KE = 0.5·m·v²= F·h
Where:
F = Force required to break the fall
Therefore the force, F = (0.5·m·v² )/h
= 0.5×75 kg ×(4.43 m/s)²/(0.0048 m) = 153319.53 N
The average force exerted on him by the ground is therefore
= 153319.53 N.