Answer:
Mechanical waves require a medium in order to transport their energy from one location to another.
Sound waves are incapable of traveling through a vacuum. Slinky waves, water waves, stadium waves, and jump rope waves are other examples of mechanical waves; each requires some medium in order to exist.
Answer:
Scientists have studied eclipses since ancient times. Aristotle observed that the Earth's shadow has a circular shape as it moves across the moon. He posited that this must mean the Earth was round. Another Greek astronomer named Aristarchus used a lunar eclipse to estimate the distance of the Moon and Sun from Earth
Answer:
208.33 W
141.26626 seconds
Explanation:
E = Energy =
t = Time taken = 8 h
m = Mass = 2000 kg
g = Acceleration due to gravity = 9.81 m/s²
h = Height of platform = 1.5 m
Power is obtained when we divide energy by time
The average useful power output of the person is 208.33 W
The energy in the next part would be the potential energy
The time taken would be
The time taken to lift the load is 141.26626 seconds