Hello there!
<span>Which of the following statements is TRUE?
Correct answer: </span>Light waves are electromagnetic waves and sound waves are mechanical waves.
The spiral structure of the milky way can be explained by long lived quasi-static density waves<em>, </em><em>according to the lin-shu hypothesis. </em>Curiously, the waves of higher density gas and stars (seen as spiral arms) appear to remain static as stars move around the galaxy. This explained by assuming that the gravitational disturbances cause by the 'clumping' material in the arms does not affect the gravitational field of the galaxy as whole and is therefore negligible.
source: Astrophysicist
The conservation of momentum states that the total momentum in a system is constant if there is no external force acting on the system. The total momentum in the gun bullet system is 0 so it must stay that way.
The momentum of the bullet is mv = 0.015*500=7.5
The momentum of the gun must be the same to keep the total momentum of the system equal to zero, so we know that p = 7.5 for the gun.
Substituting this in we get:
7.5=3.1x
x=7.5/3.1
x=2.42
So the speed of the gun is 2.4m/s.
True.
Conductivity is the ability to transmit heat, electricity or sound. Conductivity is a physical property.
A physical property is one which can be measured or observed without changing the composition or identity of a the substance.
Conductivity is a physical property because the composition of the substance does not change.
A copper wire is still a copper wire when it is conducting electricity. Like wise, an aluminum rod is still an aluminum rod when heated. It is conducting heat but the heat does not change it, it is still an aluminum rod during the whole process.
The answer is "Three".
At the point when individuals take studies for factual purposes or when the Statistics Agency comes around and gets everyone's data, data from one individual is one information point for them. Toward the finish of its exploration or overview, the organization will have accumulated numerous bits of data from numerous individuals. One piece of information equals with one data point.
