The Greeks thought that the sun was the center of the Univesre for plantets like earth to observe it !!!
It’s doesn’t change meaning it’s 0
Answer:
14.14 m/s
Explanation:
As total mechanical energy is conserved, if the potential energy is the same at Chad's position no matter if the ball is travelling up or down, then its kinetic energy, and speed, is also the same too.
Therefore, the ball would have a speed of 10m/s when it's passing Chad the 1st time. Since we know that Chad is at 5m high from the release point, we can use the following equation of motion:

where v = 10 m/s is the velocity of the ball when it passes Chad, v_0 is the initial velocity of the ball when it releases, g = 10 m/s2 is the deceleration of the can, and
is the distance traveled between Nicole and Chad. We can solve for v0:




Explanation :
The points regarding the gravitational waves are as follows :
(1) Gravitational waves are predicted to travel through space at the speed of light. So, the speed of gravitational waves is also equals
.
(2) The first direct detection of gravitational waves came in 2015. It is detected using a advanced LIGO detectors.
(3) The existence of gravitational waves is predicted by Einstein's general theory of relativity.
Hence, the correct options are (B), (D) and (E).