Answer:
The correct answer is option 'd': The frequency decreases and the intensity of the sound decreases.
Explanation:
1) <u>Effect on Frequency </u>
According to Doppler's effect of sound we have
for a source of sound moving away from the observer the relation between the observed and the original frequency is given by
where
c = speed of sound in air
is the velocity of observer of sound
is the velocity of source of sound
is the original frequency of sound
As we see the ratio is less than 1 thus the frequency of sound that the observer receives is less than that of source.
2) <u>Effect on Intensity:</u>
At a distance 'r' from source emitting a wave of Power 'P' is given by
As we see on increasing 'r' intensity of sound decreases.
Answer:
<em>C. the blue colour of the Earth's sky</em>
<em></em>
Explanation:
The Pleiades is a cluster of sister stars that are among the closest star cluster to earth.
The reflection nebula of the Pleiades is due to the scattering of the blue light from the hot blue luminous stars that dominate the star cluster. Th blue light is scattered from dust molecules, thought to be predominantly carbon compound like diamond dusts, and other compounds like iron.
The blue colour of the Earth's sky is the closest terrestrial phenomenon to the reflection nebula. On a clear cloudless day, molecules in the air scatter the blue component of light more than the other component colours of white light, giving the sky its characteristic blue coluor.
The common characteristics of the luminous nebula and the Earth's blue sky is that they both have their light scattered by the presence of small particles.
Answer:
Explanation:
given,
mass of spaceship(m) = 8600 Kg
Mass of earth = 5.972 x 10²⁴ Kg
position of movement of space ship
R₁ = 7300 Km
R₂ = 6700 Km
the kinetic energy of the spaceship increases by = ?
Increase in Kinetic energy = decrease in potential energy
Answer:
La velocidad angular del niño y del carrusel cuando se mueven juntos es 0.208 radianes por segundo.
Explanation:
Asumamos que tanto el niño como el carrusel no tienen carga externa aplicada sobre aquellos, de modo que se puede aplicar el Principio de Conservación de la Cantidad de Movimiento Angular:
(1)
Donde:
- Masa del niño, medida en kilogramos.
- Velocidad lineal inicial del niño, medida en metros por segundo.
- Radio máximo del carrusel, medida en metros.
- Momento de inercia del carrusel, medida en kilogramo-metros cuadrados.
- Velocidad angular final del sistema niño-carrusel, medida en radianes por segundo.
Si sabemos que 
, 
, 
y 
, tenemos que la velocidad angular final es:
La velocidad angular del niño y del carrusel cuando se mueven juntos es 0.208 radianes por segundo.
Answer:
a) v = √ g x
, b) W = 2 m g d
, c) a = ½ g
Explanation:
a) For this exercise we use Newton's second law, suppose that the block of mass m moves up
T-W₁ = m a
W₃ - T = M a
w₃ - w₁ = (m + M) a
a = (3m - m) / (m + 3m) g
a = 2/4 g
a = ½ g
the speed of the blocks is
v² = v₀² + 2 ½ g x
v = √ g x
b) Work is a scalar, therefore an additive quantity
light block s
W₁ = -W d = - mg d
3m heavy block
W₂ = W d = 3m g d
the total work is
W = W₁ + W₂
W = 2 m g d
c) in the center of mass all external forces are applied, they relate it is
a = ½ g
