Explanation:
It is given that,
A helicopter blade spins at exactly 100 revolutions per minute.
Its tip is 5.00 m from the center of rotation, r = 5 m
(a) Let v is the average speed of the blade tip in the helicopter’s frame of reference. Distance covered by the helicopter, 
In 100 revolutions, 
So, average speed of the blade tip in one second is given by :


v = 52.35 m/s
(b) The average velocity over one revolution is zero because the net displacement in one rotation is 0.
Hence, this is the required solution.
Explanation:
Assuming no air resistance, the horizontal acceleration at all points is 0, and the vertical acceleration at all points is -g (if near the surface of the Earth, -9.8 m/s²).
The difference between true north and magnetic north is called "declination."
Scientists study fossils of plants, animals, and other organisms in order to better understand what life was like on Earth many years ago and how it has changed over time. Fossils are important evidence for the theory of evolution.