Answer:
Train will take 156 sec to travel 12km.
Answer:

Explanation:
By Snell's law we know at the left surface




now we have


now on the other surface we know that
angle of incidence = 

so again we have

so we have


also we know that


By solving above equation we have

Answer:
The speed traveled by the car is 40 meter per second.
Explanation:
The formula for the relation between the power and the force is as follows:
P = Fv
Where F is the force and v is the speed.
As given
To travel at constant speed, a car engine provides 24KW of useful power. The driving force on the car is 600N.
F = 600 N
Convert power from KW to W.
1 KW = 1000 W
24 KW = 24 × 1000 W
= 24000 W
Thus
P = 24000 W
Put these values in the formula.
24000 = 600 × v
24000 = 600v

v = 40 meter per second .
Therefore the speed of the car is 40 meter per second .
The wavelength of the third line in the Lyman series, and identify the type of EM radiation
In this series, the spectral lines are obtained when an electron makes a transition from any high energy level (n=2,3,4,5... ). The wavelength of light emitted in this series lies in the ultraviolet region of the electromagnetic spectrum.
1 / lambda = R(h)* (
-
)
= 109678 (
-
)
= 109678 (8/9)
Lambda = 9 / (109678 * 8 )
= 102.6 *
m = 102.6 nm
To learn more about Lyman series here
brainly.com/question/5762197
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