In this case, you simply use subtraction to find out the velocity. If the plane is flying at 395 km/h and is being blown by 55 km.h wind the other way, the velocity of the plane is 395 - 55.
395 km/h - 55 km/h = 340 km/h
So, the final velocity of the plane is 340 km/h east.
Answer: D. 
Explanation:
The energy
of an electromagmetic wave is given by:
Where:
is the Planck constant
is the speed of light in vacuum
Then 
is the wavelength
Solving:
Answer:Sound travel faster in warm room.
Explanation:The speed of sound depends on the temperature of the medium. Mathematically, the relation between the speed of the sound and the temperature is give by:v=
is the ratio of the specific heats
R is the gas constant
T is the temperature of the medium
We know that the temperature of the warm room is more as compared to the cold room.
So, it is clear that the sound travel faster in a warm room. The particles move faster when the temperature is high.
Answer:
D. absolute magnitude and apparent magnitude