Explanation:
Echoes occur due to the reflection of sound from any obstacle, but not all the reflected sound waves lead to the phenomenon of echo. For the echo to be heard it actually depends upon the human perception as well, human ears can encounter the difference between the sound wave directly form the source and the reflected sound waves only if there is a minimum time gap of one-tenth of a second. For this time gap in the atmosphere at normal temperature and pressure the obstacle must be at least 7 meters away from the sound source.
Answer:
D.
Explanation:
Specifically, Special Relativity showed us that space and time are not independent of one another but can be mixed into each other and therefore must be considered as the same object, which we shall denote as space-time. The consequences of space/time mixing are: time dilation. and length contraction.
Answer:
1027 N/C
3.42 x 10⁻⁶ T
Explanation:
I = Intensity of electromagnetic field = 1400 W/m²
E₀ = Maximum value of electric field
Intensity of electromagnetic field is given as
I = (0.5) ε₀ E₀² c
1400 = (0.5) (8.85 x 10⁻¹²) (3 x 10⁸) E₀²
E₀ = 1027 N/C
B₀ = maximum value of magnetic field
using the equation
E₀ = B₀ c
1027 = B₀ (3 x 10⁸)
B₀ = 3.42 x 10⁻⁶ T
ummmm it might be 300... i used a calculator
sorry if it is wrong
