KE = 1/2 x 80 x 60^2
KE = 144000
        
                    
             
        
        
        
I think shock waves require more speed they travel at the speed of sound
 
        
                    
             
        
        
        
Answer:
a) 46.5º  b) 64.4º 
Explanation:
To solve this problem we will use the laws of geometric optics
a) For this part we will use the law of reflection that states that the reflected and incident angle are equal
      θ = 43.5º
This angle measured from the surface is
      θ_r = 90 -43.5
      θ_s = 46.5º
b) In this part the law of refraction must be used
      n₁ sin θ₁ = n₂. Sin θ₂
      sin θ₂ = n₁ / n₂ sin θ₁
The index of air refraction is n₁ = 1
The angle is this equation is measured between the vertical line called normal, if the angles are measured with respect to the surface
      θ_s = 90 - θ
      θ_s = 90- 43.5
      θ_s = 46.5º
      sin θ₂ = 1 / 1.68  sin 46.5
      sin θ₂ = 0.4318
      θ₂ = 25.6º
The angle with respect to the surface is
      θ₂_s = 90 - 25.6
      θ₂_s = 64.4º
measured in the fourth quadrant
 
        
             
        
        
        
Answer:
Explanation:
I think the answer is statement no 3.
Hope it helps.