Sound is an example of a mechanical wave. Mechanical waves are the kinds of waves that cannot be propagated without a medium. As such, these waves cannot travel through a vacuum, just like how sound cannot travel through space, since space is a vacuum.
Answer:
D) the bending of a wave as it moves around an obstacle or passes through a narrow opening
Explanation:
Even though light travels in straight line, it will bend around objects if their size is comparative to its wavelength. This phenomenon is called diffraction.
Light will also bend if the light travels from one medium to another medium at an angle, but that is called refraction.
Diffraction occurs in one medium. Refraction occurs when light travels from one medium to another.
Answer:
Explanation:
Temperature of the house, 
Convert to rankine, 
Heat is extracted at 40°F i.e 
Calculate the coefficient of performance of the heat pump, COP
The minimum power required to run the heat pump is given by the formula:
...............(*)
Where the heat losses from the house, 
Substituting these values into * above
data which is expressed in form of following way
here in above expression
= true value
= uncertainty in the value
now the relative uncertainty is given as
now by above formula we can say
a) 2.70 ± 0.05cm
here
True value = 2.70
uncertainty = 0.05
Relative uncertainty = 
= 0.0185
b) 12.02 ± 0.08cm
here
True value = 12.02
uncertainty = 0.08
Relative uncertainty = 
= 0.00665
Answer:
Explanation:
En la zona apótica (profundidad inferior a 200 m); todo lo que queda de la luz solar es una luz tenue, opaca, azul-verde, demasiado impotente para siquiera considerar permitir que ocurra la fotosíntesis. Sin embargo, hay comida para tener; basura, trozos de plantas podridas y derroche de criaturas caen desde arriba para cuidar a los seres vivos en la zona apótica.
Las formas de vida a una profundidad inferior a 200 m dependen de los productos químicos que salen de los respiraderos; el procedimiento que utilizan para hacer los alimentos se llama quimiosíntesis en lugar de fotosíntesis.
