Answer:
11.1 m/s
Explanation:
120 km = 120 x 1,000 = 120,000 m 
3 hours = 3 x 60 x 60 = 3600 x 3 = 10,800 s
speed = 120,000 / 10,800
= 1200/108
= 11.1 m/s
 
        
                    
             
        
        
        
Explanation:
tilting it will raise the height of its center of gravity. 
 
        
             
        
        
        
Answer:
A. These vibrations can travel through solids, liquids, and gases, but not through <u>empty</u><u> </u><u>space</u>.
 
        
             
        
        
        
Answer:
A, total.
<em>The </em><em>total</em><em> energy in a mechanical system is determined by adding the potential and kinetic enters together.</em>
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<u><em>i hope this helped at all.</em></u>
<em />
 
        
             
        
        
        
Answer:
Explanation:
Let the velocity after first collision be v₁ and v₂ of car A and B . car A will bounce back . 
velocity of approach = 1.5 - 0 = 1.5 
velocity of separation = v₁ + v₂ 
coefficient of restitution = velocity of separation / velocity of approach
 .8 = v₁ + v₂ / 1.5 
v₁ + v₂ = 1.2 
applying law of conservation of momentum 
m x 1.5 + 0 = mv₂ - mv₁
1.5 = v₂ - v₁
adding two equation 
2 v ₂= 2.7 
v₂ = 1.35 m /s 
v₁ = - .15 m / s 
During second collision , B will collide with stationary A . Same process will apply in this case also. Let velocity of B and A after collision be v₃ and v₄. 
For second collision , 
coefficient of restitution = velocity of separation / velocity of approach
 .5 = v₃ + v₄ / 1.35 
v₃ + v₄ = .675
applying law of conservation of momentum 
m x 1.35 + 0 = mv₄ - mv₃
1.35 = v₄ - v₃
adding two equation 
2 v ₄= 2.025
v₄ = 1.0125 m /s 
v₃ = - 0 .3375  m / s