Answer:
637 km/h, not reasonable
Explanation:
Total average speed = 91 km/h
Average speed of first half, v1 = 49 km/h
Let the average speed for the next half is v2.
Let the total distance is 2s.
Time taken for first half of the journey, t1 = s / v1 = s / 49
Time take for the next half of the journey, t2 = s / v2
The average speed is defined as the total distance traveled to the total time taken
[tex]\frac{1}{v_{2}}=\frac{7}{4459}
v2 = 637 km/h
This is very high speed which is not reasonable.
Photon
energy is the energy carried by a single photon with a certain wavelength and
frequency. These terms are related by an equation. <span>
E = hv
<span>where h is the Planck's constant (6.626 x
10-34 J s), v is the frequency which is related to the wavelength by:
λv = c where λ is the wavelength and c is the speed of light (3.00 x
108 m/s)
</span>
Therefore, the energy equation
<span>E = hc / λ
E = (6.626 x 10-34 J s)(3.00 x 10^8 m/s) / 0.0120 m = <span>1.657 x 10^-23 J</span></span></span>
I think the answer will be 7% or 7J. not sure :-)
D. Mechanical waves need to have a medium