Answer:
Workdone =0
Explanation:
The body is inclined at θ=30°,     s=10m,  m=5kg
Workdone by the object = FsCosθ
but the surface is a friction-less surface, this means coefficient of friction =0
F=μR
F=0*R
F=0
W=FScosθ
W=0*SCosθ
W=0
 
        
             
        
        
        
Answer:
shadow is formed when an opaque object comes on path of light shadows are formed because light travels in a straight line and it can't pass through an opaque object
 
        
                    
             
        
        
        
1.6 m/s west is the answer 
 
        
             
        
        
        
 Explanation : Explain each characteristic of sound waves.
Intensity : the intensity of the sound wave is understand as the power carry by sound wave per unit area in the direction perpendicular to that area.
Loudness :  loudness is the quality of the loud and soft of the sound wave.
Frequency : Human normal hear sound frequency between 20 Hz to kHz. 
Pitch : Pitch is the quality of low and high of sound wave . pitch relates to the frequency of the slowest vibration in the sound wave for simple sound.
 
        
                    
             
        
        
        
The correct answer is matter. Matter is a physical substance, so it is that only option provided that can be broken down to the subatomic particle level.