We are given an electromagnetic wave with a frequency of 5.09 x 10^14 Hz and travelling through a transparent medium. If the medium was vacuum, the speed of the wave would be equal to the speed of light. Otherwise, the main factor that would determine the speed of the wave is its wavelength.
Answer:
a) 6.95 m/s
b) 1.42 seconds
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.81 m/s²

a) The vertical speed when it leaves the ground. is 6.95 m/s

Time taken to reach the maximum height is 0.71 seconds

Time taken to reach the ground from the maximum height is 0.71 seconds
b) Time it stayed in the air is 0.71+0.71 = 1.42 seconds
Well, first of all, I don't think "After the collapse of a nebular cloud ..."
is the first time that "atoms begin gravitating together". Seems to me like
that's what was going on all the time, and it's what caused the nebular cloud
to collapse in the first place.
In any case, once the pressure and temperature at the center get high enough,
you get "ignition" of nuclear fusion, and that's when you first have a "star".
Answer:
η = 0.882 = 88.2 %
Explanation:
The efficiency of the pulley system can be given as follows:

where,
η = efficiency of pulley system = ?
W_out = Output Work = (600 N)(0.6 m) = 360 J
W_in = Input Work = (35.7 N)(11.43 m) = 408.051 J
Therefore,

<u>η = 0.882 = 88.2 %</u>
Answer: Negatively charged particles are repelled by other negatively charged particles
Explanation: