Well the US doesn't naturally have a lot of fossil fuels so we rely on other countries who do have fossil fuels. So if we aren't that friendly with Saudia Arabia (they have a bunch of oil) then they can hike up the prices or cut us off from their oil supply completely which would cripple the US severly. So with that being said, we NEED other countries, and the big question is when will they not NEED us. At any point in which they feel that they don't need us they can just cut us off, which would be bad.
Hope that helps :)
 
        
                    
             
        
        
        
Answer:
It can relieve stress and improve mood.
 
        
                    
             
        
        
        
I can help you with 5. 5 is a displacement-time graph. 
At A it is moving in a positive direction and speed is constant. 
At B it is stationary or at rest. 
At C, movement is negative and it is decreasing or decelerating 
At D, it’s a general downwards movement in the negative direction that can be described as overall constant
        
             
        
        
        
Answer:
a = 2 m/s2
Explanation:
we know from newtons 2nd law 
 F = ma. 
we also know that from hookes law we have 
 F = kx
equate both value of force to get value of acceleration
 kx = ma, 
where,
k is spring constant = 8.0 N/m
x is maximum displacement  0.10 m
m is mass of object 0.40 kg
a = \frac{kx}{m}
      = \frac{8 *0 .10}{0.40}
a = 2 m/s2
 
        
             
        
        
        
Answer:
160 kg
12 m/s
Explanation:
 = Mass of first car = 120 kg
 = Mass of first car = 120 kg
 = Mass of second car
 = Mass of second car
 = Initial Velocity of first car = 14 m/s
 = Initial Velocity of first car = 14 m/s
 = Initial Velocity of second car = 0 m/s
 = Initial Velocity of second car = 0 m/s
 = Final Velocity of first car = -2 m/s
 = Final Velocity of first car = -2 m/s
 = Final Velocity of second car
 = Final Velocity of second car
For perfectly elastic collision

Applying in the next equation


Mass of second car = 160 kg
Velocity of second car = 12 m/s