<span>when it returns to its original level after encountering air resistance, its kinetic energy is
decreased.
In fact, part of the energy has been dissipated due to the air resistance.
The mechanical energy of the ball as it starts the motion is:
</span>

<span>where K is the kinetic energy, and where there is no potential energy since we use the initial height of the ball as reference level.
If there is no air resistance, this total energy is conserved, therefore when the ball returns to its original height, the kinetic energy will still be 100 J. However, because of the presence of the air resistance, the total mechanical energy is not conserved, and part of the total energy of the ball has been dissipated through the air. Therefore, when the ball returns to its original level, the kinetic energy will be less than 100 J.</span>
Answer:
Time according to earth clock (T0) = 0.22 years (Approx)
Explanation:
Given:
Time taken by light = 4.5 years
Time taken by ship = 5 years
Speed of light = c
Speed of ship (v) = 90% of c = 0.9c
Find:
Time according to earth clock (T0) = ?
Computation:
Time dilation is ,

Time according to earth clock (T0) = 0.22 years (Approx)
The flashlight is powered by one or more batteries.
Batteries supply Direct current (DC) .
Well, to be honest, there is no official way to find out which volcano erupted recently as scientists don't have that type of equipment ready or in use at all; also there is no official way [...] because there are always eruptions occurring.
If you want the most known, "Calbuco" is your answer. It erupted in 2014 and it is found in Chile.