Answer:
The first flowering plants appeared in the Mesozoic era, not the Paleozoic era.
Explanation:
The Mesozoic era was an era where numerous organisms started to develop in very unique and more advanced ways, both the animals and the plants. In the last period of the Mesozoic, the Cretaceous, the first flowering plants started to appear on the scene. This was revolutionary trait of the plants, and soon these plants started to occupy more and more space and became one of the dominant organisms on the planet. Other important evolution that took place in this period are the appearance of the dinosaurs and the mammals, both becoming the dominant animals on the planet, first the dinosaurs, after that the mammals.
I believe the answers you're looking for is effectively but not efficiently. The reason its these choices is because although you finished the job, it was not done in the best way possible. So it was effective, but not efficient.
Answer:
390 J
Explanation:
m = 3 kg
u = 16 i + 2 j
(a) Magnitude of velocity =
= 16.1245 m/s
KEi = 1/2 m v^2 = 0.5 x 3 x 16.1245 = 390 J
(b) v = 18 i + 14 j
Magnitude of velocity =
= 22.804 m/s
KEf = 1/2 m v^2 = 0.5 x 3 x 22.804 = 780 J
According to the work energy theorem
Work done = change in KE = KEf - KEi = 780 - 390 = 390 J
√10(√10) = √10^2
The root and the square cancels:
√10^2 = 10
10 is your answer
hope this helps
The average angular acceleration of the fan is

The number of revolutions after time
is given by

Acceleration is assumed to be constant, so
and over the 2 second interval we have

so the answer is A.