The correct answer is Option C) Sample C would be best, because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest.
As the coefficient of absorption would define the energy present in the reflected wave, the material C has the highest percentage of absorption i.e. 62% and would be best suitable to make a sound proof room.
We use the kinematic equations,
(A)
(B)
Here, u is initial velocity, v is final velocity, a is acceleration and t is time.
Given,
,
and
.
Substituting these values in equation (B), we get
.
Therefore from equation (A),

Thus, the magnitude of the boat's final velocity is 10.84 m/s and the time taken by boat to travel the distance 280 m is 51.63 s
Velocity = (displacement) / (time)
Displacement = straight-line distance between start-point and end-point
If you stop at the same point you started from, then
your displacement for the trip is zero, and your average
velocity is also zero.
Answer:
In hot gases , the atoms keeps colliding with each other and sometimes the energy liberated during collision takes the electron to a higher level,thus, .The object is a cloud of hot gas and finally the electron returns back emitting photon
As we know by Doppler's effect of light we have

here we will have
[tex}\frac{398.1 nm - 396.9 nm}{398.1 nm} = \frac{v}{c}[/tex]
here by solving above we have

here we have

since wavelength is increased so we can say that it is moving away
so correct answer is
1- 904.3 km/s away from the Earth