The power is defined as the work done (W) by the transmission per unit of time (t) to accelerate the train:
To find the work done, we can use the work-energy theorem, which states that the work done is equal to the variation of kinetic energy of the train. Since the trains starts from rest, its initial kinetic energy is zero, so the work done is simply equal to the final kinetic energy:
where m is the mass of the train and
is its final velocity.
The mass of the train is m=0.875 kg while its final velocity is
, the work done by the electrical transmission is
And since this work is done in a time of t=20.5 ms=0.0205 s, the minimum power delivered is
It depends, one can be darker or lighter. There can be many colors of shade, there can also be different patterns of shade.
Answer:
Explanation:
in your textbook, they have a formula like this:
g=mass of earth*G/R^2
G=6.67*10^-11
apply to this
we have g=6*10^2*4*6.67*10^-11/(6.4*10^3*1000)^2=9.78