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:
Only 2,3,4 are true
Explanation:
Bosons Particles are particles that condense to the same state. Bosons particle have integral spin like 0 , 
, 
, 
, etc. Bosons particles always have asymmetric wave function and there is exchange of particles.
1) It does not obey Fermi_ Dirac statistics
2) It obeys Bose-Einstein statistics
3) The object can have intrinsic spin
4) Yes the Bosons particle is always symmetric with exchange of particles
5) No Bosons particle are symmetric and not asymmetric
Answer:
Spiral galaxies consist of a flat, rotating disk of stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.
Elliptical galaxies have smooth, featureless light-profiles and range in shape from nearly spherical to highly flattened, and in size from hundreds of millions to over one trillion stars. In the outer regions, many stars are grouped into globular clusters. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity They are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies.
irregular galaxies were once spiral or elliptical galaxies but were deformed by gravitational action. they are shapeless.
Answer:
Check image.
Explanation:
This is what my solution is, not a professional tutor so take my answer with a grain of salt and check.
Answer:
I = 1.4kgm²
Explanation:
The rotational motion is caused by the frictional force, which generates a torque on the system. As there is no other force that creates a torque, this can be expressed in the equation of rotational motion below:
And 
, where r is the distance from the point of application and the rotation axis, and f is the magnitude of the frictional force. This is because the frictional force is applied in the direction that causes the greatest angular acceleration (this is, 90°) and 
. Then, we have that:
Plugging in the given values, we obtain:
In words, the total moment of inertia is equal to 1.4kgm².
