My answer -
I believe that the answer is (A).
P.S
Happy to help you have an AWESOME!! day 
        
             
        
        
        
Answer:
Radioactive decay is the spontaneous breakdown of an atomic nucleus resulting in the release of energy and matter from the nucleus. Remember that a radioisotope has unstable nuclei that does not have enough binding energy to hold the nucleus together.
Explanation:
 
        
             
        
        
        
Answer: Option (C) is the correct answer.
Explanation:
As we know that metals are able to conduct electricity so, when a negatively charges rod is kept closer to the left sphere then electrons will enter the sphere. 
Since, like charges repel each other. Hence, some of the negative changes from the rod will repel the negative charges of left sphere. 
As both left and right spheres are touching each other so, the electrons will move towards the right sphere. As a result, there will be too many electrons (negative charge) present on the right sphere and very less electrons present in the left sphere.
Thus, we can conclude that the statement right sphere is negatively charged, another is charged positively, is true.
 
        
                    
             
        
        
        
Answer:
a. 
b. 
Explanation:
a) 
F= 120,000N
Kinetic energy @ impact = 120,000*depth
 


b) 
The momentum is equal to the impulse on him from the snow so:


