Explanation:
Wave is defined as a disturbance or oscillation that travels through space-time, accompanied by a transfer of energy. Wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium.
The velocity of wave is equal to the product of its wavelength and frequency (number of vibrations per second). Longitudinal waves like sound waves travel through a medium.
Therefore, a wave move from a layer of high velocity to that of a lower velocity the wavelength changes (that is, decreases) as it moves.
This is a concept of momentum. In equation, momentum is the product of force and distance. When a ball is thrown, its force is constant all throughout unless disturbed by an external force. Therefore, force is the constant of proportionality that relates momentum with distance. When you block a ball from a given distance, you would feel the great force on your hand. In order to reduce the force, you have to follow the direction of the force in order to minimize the impact. By doing this, you gradually decrease the momentum of the ball.
Answer:
In a unit government, all the powers of government are moved around in the central government where in turn in a federal government, the powers of government are divided between the center and the units.
Explanation:
I hope this helps.
Answer:
(d) A strong electron-phonon interaction
Explanation:
Superconductivity -
The phenomenon of superconductivity is due to the attractive force between electrons from the exchange of the phonons that cause the bound pair of electrons known as cooper pairs .
A strong electron -phonon intercation is suitable condition for superconductivity and high resistance .
Answers:
a) 
b) 
Explanation:
a) The centripetal acceleration 
of an object moving in a uniform circular motion is given by the following equation:
Where:
is the angular velocity of the ball
is the radius of the circular motion, which is equal to the length of the string
Then:
This is the centripetal acceleration of the ball
b) On the other hand, in this circular motion there is a force (centripetal force 
) that is directed towards the center and is equal to the tension (
) in the string:
Where 
is the mass of the ball
Hence:
This is the tension in the string
