Answer:
1.08 s
Explanation:
From the question given above, the following data were obtained:
Height (h) reached = 1.45 m
Time of flight (T) =?
Next, we shall determine the time taken for the kangaroo to return from the height of 1.45 m. This can be obtained as follow:
Height (h) = 1.45 m
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =?
h = ½gt²
1.45 = ½ × 9.8 × t²
1.45 = 4.9 × t²
Divide both side by 4.9
t² = 1.45/4.9
Take the square root of both side
t = √(1.45/4.9)
t = 0.54 s
Note: the time taken to fall from the height(1.45m) is the same as the time taken for the kangaroo to get to the height(1.45 m).
Finally, we shall determine the total time spent by the kangaroo before returning to the earth. This can be obtained as follow:
Time (t) taken to reach the height = 0.54 s
Time of flight (T) =?
T = 2t
T = 2 × 0.54
T = 1.08 s
Therefore, it will take the kangaroo 1.08 s to return to the earth.
We can solve the problem by using the first law of thermodynamics:
where
is the change in internal energy of the system
is the heat absorbed by the system
is the work done by the system on the surrounding
In this problem, the work done by the system is
with a negative sign because the work is done by the surrounding on the system, while the heat absorbed is
with a negative sign as well because it is released by the system.
Therefore, by using the initial equation, we find
2/5 = .4
.4*100= 40%
Alex spends more time
Answer:
Explanation:
Evolution is both a fact and a theory. Evolution is widely observable in laboratory and natural populations as they change over time. The fact that we need annual flu vaccines is one example of observable evolution. At the same time, evolutionary theory explains more than observations, as the succession on the fossil record. Hence, evolution is also the scientific theory that embodies biology, including all organisms and their characteristics. In this paper, we emphasize why evolution is the most important theory in biology. Evolution explains every biological detail, similar to how history explains many aspects of a current political situation. Only evolution explains the patterns observed in the fossil record. Examples include the succession in the fossil record; we cannot find the easily fossilized mammals before 300 million years ago; after the extinction of the dinosaurs, the fossil record indicates that mammals and birds radiated throughout the planet. Additionally, the fact that we are able to construct fairly consistent phylogenetic trees using distinct genetic markers in the genome is only explained by evolutionary theory. Finally, we show that the processes that drive evolution, both on short and long time scales, are observable facts.
