Momentum = mass x velocity
Thus Option A is the correct answer 
Momentum (dog)  = 10 kg x (0.447 x 30) m/s
= 134.1 Kg m/s
Momentum ( bullet)  = 0.02 kg x (0.447 x 800) m/s
= 7.152 Kg m/s
Momentum ( truck) = 0, as v = 0
tightrope has both low mass  and low speed, thus its momentum will be low
 
        
             
        
        
        
Mass- Mass is measured in kilograms (kg). 
Weight- Weight is measured in Newton’s.
        
                    
             
        
        
        
The other 4 kg of mass may have departed the scene 
of the fire, in the form of gases and smoke particles.
        
             
        
        
        
The answer is true
<span>Nuclear Fusion is 2 small nuclei to form one that's bigger</span>
        
                    
             
        
        
        
The blades that spin around in the fan, because they are flat and produce work