Answer:
Explanation:
b ) The problem is based on Doppler's effect of sound
f = f₀ x (V - v₀) /( 
)
f is apparent frequency ,f₀ is real frequency , V is velocity of sound , v₀ is velocity of observer going away , 
is velocity of source going away
778 = 840 x (340 - 14)/ (340 + )
340 + = 341.18
= 1.18 m /s
it will go away from the observer or the cyclist.
speed of train = 1.18 m /s
a )
For a stationary observer v₀ = 0
f = f₀ x V /( )
= 840 x 340 / (340 + 1.180)
= 837 Hz
Answer:
Explanation:
The direction of propagation of electromagnetic wave
is given by the direction of vector E x B where E is electrical field , B is magnetic field .
Given Electric field = E i because it is along x axis
Magnetic field = Bj because it is along y axis
E x B = Ei x Bj
= EB k .
so direction of E x B is along k direction or z - axis so wave is propagating along z - axis .
Answer:
2.24 seconds
Explanation:
xf = xo + vo t + 1/2 at^2
45 = 0 + 15 t + 1/2 (4.5) t^2
2.25 t^2 + 15t - 45 = 0 Quadratic formula shows t = 2.24 seconds
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