Answer:
The distance between the ships changing at 6PM is 21.29Km/h
Explanation:
Ship A is sailing east at 35Km/h and ship B is sailing West at 25Km/h
Given
dx/dt= 35
dy/dt= 25
dv/dt= ???? at t= 6PM - 2PM= 4
Therefore t=4
We know ship A travels at 150km in the x-direction and Ship A at t=4 travels at 4.35 Which is 140 also in x-direction
So, we use:
;

But ship B travels at t=4, at 4.25 =100 in the y-direction
so, let's use the equation:


Lets use 2DD' = 2xx' + 2yy'
Differentiating with respect to t we have:
D•d(D)/dt = -(10)•dx/dt + 100•dy/dt
=100.5 d(D)/dt = (-10)•35 + (100)•25
When t=4, we have x=(140-150) =10 and y=100

=100.5
= 100.5 dD/dt = 10.35 +100.25
= dD/dt = 21.29km/h
Answer:
A. 
B. 
Explanation:
The frequency has an inversely proportional relationship with the concept of wavelength, the greater the wavelength, the lower the frequency. For electromagnetic waves, the frequency is equal to the speed of light, divided by the wavelength.

A.

B.

Answer:
601 nm
Explanation:
Energy of photon having wavelength of λ nm
=
eV
Energy of 249 nm photon
=
=4.996 eV
Similarly energy of 425nm photon
=
=2.927 eV
Difference = 2.069 eV.
This energy will give rise to another photon whose wavelength will be
λ = 
= 601 nm.
The answer is nodes because nodes stay in a fixed position and i just learnt about this!