Answer:
<h3>How did scientists “discover” Pangea and other supercontinents of the past?</h3>
Nowadays, they can study the geologic record and use radioactive dating, seismic surveys, and other technologies to construct maps of how the world looked at various points in Earth's history.
Answer:
E. greater than the angle of incidence.
Explanation:
Snell's law states that:
(1)
where
are the refractive index of the first and second medium
are the angle of incidence and refraction, respectively
For light moving from water to air, we have:
(index of refraction of water)
(index of refraction of air)
Substituting into (1) and re-arranging the equation, we get
which means that
so, the correct answer is
E. greater than the angle of incidence.
Answer:
B) The total number of atoms does not change, so mass is conserved in the reaction.
Explanation:
According to the <u><em>Law of Conservation of Mass</em></u>, no matter can ever be created or destroyed. The number of atoms does not change, thus the mass does not change.
Answer:
12500W
Explanation:
Given parameters:
Work done = 250000J
Time taken = 20s
Unknown:
Power of the crane = ?
Solution:
Power is the defined as the rate at which work is being done;
Mathematically;
Power = 
insert the parameters and solve;
Power = 
= 12500W
At the highest point: kinetic energy is 0 due to the speed is 0
So the total mechanical energy is 20
Assume no frictions present, then the mechanical energy is conserved
So at the lowest point, kinetic energy = mechanical energy - potential energy
Answer will be 20 - 0.5 = 19.5 J
