20 ohms in parallel with 16 ohm= 8.89
20x16/20+16. Product over sum
Answer:

Explanation:
When wings of the airplane makes an angle of 40 degree with the horizontal so here we can say that force due to air is having two components


now we know that


also we know that


now plug in all data in above equations




Answer:
The distance between earthquake center and the measuring station is 1350 kilometers.
Explanation:
Let the earthquake center be at a distance of 'S' meters from the recording station.
Now from the basic relation of distance, speed and time we know that

For a Primary wave (P wave) let us assume that it appraoches the measuring station after
minutes
Thus making use of the above relation we have

Now since it is given that the secondary wave (S wave) reaches the measuring spot after 2 minutes or 120 seconds thus the time taken by secondary waves to reach recorder equals
making use of the same relation we get

Solving equation 'i' and 'ii' we get
Answer:
Approximately
.
Explanation:
Since the result needs to be accurate to three significant figures, keep at least four significant figures in the calculations.
Look up the Rydberg constant for hydrogen:
.
Look up the speed of light in vacuum:
.
Look up Planck's constant:
.
Apply the Rydberg formula to find the wavelength
(in vacuum) of the photon in question:
.
The frequency of that photon would be:
.
Combine this expression with the Rydberg formula to find the frequency of this photon:
.
Apply the Einstein-Planck equation to find the energy of this photon:
.
(Rounded to three significant figures.)