Answer:
Explanation:
Cutting a string in half because 
b is irreversible 
c is a cheical and d is also a chemical change
 
        
             
        
        
        
Explanation:
Since, it is given that the magnet drops and falls lengthwise towards the canter of the ring. As a result, change in magnetic flux will occur which tends to induce an electric current in the ring. 
Therefore, a magnetic field is also produced by the ring itself which will actually oppose or repel the magnet.  
Thus, we can conclude that the falling magnet be repelled by the ring due to the magnetic interaction of the magnet and the ring.
 
        
             
        
        
        
Gravitational force = G ( m1 m2 ) / r²
3 = G ( m1 m2 ) / ( 10 )²x = G ( m1 m2 ) / ( 5 )²We shall divide those two equations:3 / x = 1/100 / 1/25 = 25 / 100 = 1 / 4x · 1 = 3 · 4x = 12Answer:C. 12 N 
        
             
        
        
        
Group 0 - they are called the NOBLE GASES
(as they're very unreactive) because... 
ALL of their atoms are full.
Example : Helium contains 2 electrons so it's outer shell is full
        
             
        
        
        
Answer:C The final velocity is half of trained car B's initial velocity.
Explanation: