Answer:
Explanation:
When the positively charged half shell is brought in contact with the electroscope, its needle deflects due to charge present on the shell.
When the negatively charged half shell is brought in contact with the positively charged shell , the positive and negative charge present on each shell neutralises each other .So both the shells lose their charges .The positive half shell also loses all its charges
When we separate the half shells , there will be no deflection in the electroscope because both the shell have already lost their charges and they have become neutral bodies . So they will not be able to produce any deflection in the electroscope.
Answer:
Semi conductors are part of the fourth group in periodic table.
Explanation:
Periodic table is the arrangement of chemical elements on the basis of their atomic number. So all the elements with respective valence electrons are placed in thir respective groups. . All the elements with valence electrons four are placed in the fourth group .Semi conductors is the common name given to the elements of 4th group. These elements dont have the tendency to either donate or accept.
The group 3 elements have three electrons in their valence shell and hence have a tendency to donate. Whereas the group 5 elements having five valence electrons accept to satisfy thir octet. The semi conductors exist between 3rd and 5th groups exhibiting different properties according to the temperatures and excitations provided.
Answer: Noise above 70 dB can cause hearing damage
Explanation:
Answer:
The velocity is 
Explanation:
From the question we are told that
The mass of the ball is 
The radius is 
The force is 
The speed of the ball is 
Generally the kinetic energy at the top of the circle is mathematically represented as
=> 
=> 
Generally the work done by the force applied on the ball from the top to the bottom is mathematically represented as
Here d is the length of a semi - circular arc which is mathematically represented as
So
Generally the kinetic energy at the bottom is mathematically represented as
=> 
=> 
From the law of energy conservation
=> 
=>
