Pretty sure it is A:Light wave
As they say nothing is faster than the speed of light.
Resistance in wires is transformed into thermal energy, you can observe this fact when you are charging your phone and feel the wire is quite hot. That is a result of the resistance.
Equatorial currents are primarily westward. This is because the dominant current in the northern hemisphere has a clockwise direction, while the southern hemisphere has a counterclockwise direction. When these two currents meet at the equator, a common westward current exists.
Answer:
(a) 41.75m/s
(b) 4.26s
Explanation:
Let:
Distance, D = 89m
Gravity,
= 9.8 m/
Initial Velocity,
= 0m/s
Final Velocity,
= ?
Time Taken,
= ?
With the distance formula, which is
D =
+ 
and by substituting what we already know, we have:
89 =
×9.8×
With the equation above, we can solve for
:

Now that we have solved
, we can use the following velocity formula to solve for
:
, where
is also equals to
, so we have

By substituting
,
, and
,
We have:

Answer:
(b) In ideal condition we neglect mass of spring but in real springs mass of spring adds another factor to its time period.
since we are adding a factor of mass to the system, and frequency being inversely proportional to squared root of mass, we can come to a general conclusion that it effectively reduces the natural frequency .
Explanation:
kindly check the attachment for explanation.