A would be number 2. Newton's First Law states that an object at rest, will stay at rest and an object in motion, will stay in motion, unless acted upon by an unbalanced force. B would be number 3. His Second Law states that <span>the sum of the forces acting on a body is equal to the product of the mass of the body and the acceleration produced by the forces. And, C would be number 1. His Third Law states that for every action, there is an equal and opposite reaction. Hope this helps!</span>
        
             
        
        
        
Answer:
21s
Explanation:
Given parameters;
Radius  = 10m 
Speed or velocity  = 3m/s 
Unknown: 
Period  = ? 
Solution: 
 To solve this problem, use the expression: 
       v  =  
  
r is the radius 
T is the unknown
            Input the parameters and solve for T; 
     3  =  
  
     62.84 = 3T 
          T  = 21s
 
        
             
        
        
        
Answer:
F = 19.1 N
Explanation:
To find the force exerted by the string on the block you use the following formula:
 (1)
  (1)   
k: spring constant = 95.5 N/m
x: displacement of the block from its equilibrium position = 0.200 m
you replace the values of k and x in the equation (1):

Hence, the force exterted on the block is 19.1 N
  
 
        
             
        
        
        
Answer:
The metric system is the official system for all nations of the world.
Explanation:
To make measures, it is necessary to have a set of standardized magnitudes to compare things we want to measure. This set of standardized magnitudes is called a unit system. 
The metric system is a decimalized system of measurement which has meters and grams as a basic measurement unit. The metric system is the most used in the world, and also, is the official system for all nations of the world.