v = speed of the source of sound or the train towards the listener or switchman = 40 m/s
V = actual speed of sound = 340 m/s
f = actual frequency of sound as emitted from source or the train = 1000 Hz
f' = frequency as observed by the listener or by switchman = ?
Using Doppler's law , frequency observed by a listener from a source moving towards it is given as
f' = V f /(V - v)
inserting the values
f' = 340 x 1000 /(340 - 40)
f' = 340 x 1000/300
Answer:
C) Index of refraction
Explanation:
Index of refraction also known as refractive index is defined as speed of light in a vacuum divided by the speed of light in a given material.
The formula for Index of refraction is:
n = c ÷ v
where n represents Index of refraction,
c represents speed of light in a vacuum,
v represents speed of light in a given material.
The speed and direction of light changes when it moves from one medium to another. The change in direction is basically called refraction.
Answer:
C
Explanation:
To melt the alcohol
Heat needed = M . L = 2 . 25 = 50 kcal
To warm up the alcohol
Heat needed = M . sp. ht. . ∆t = 2 . 0.6 . 100 = 120 kcal
Total heat needed = 170 kcal
Assuming that 0.6 kcal/ kg / ˚C is the specific heat and that the answer is wanted in kcal ( a rather odd unit to be in use here.)
Answer:
if you look it up i think u can find it it could be a mealltiod Co 27
Explanation:
