As per Definition of acceleration we know that rate of change in velocity of object is known as acceleration

so when we apply push on an object that push or applied force will change the velocity of object always
so correct answer must be
a.) changed the velocity
 
        
                    
             
        
        
        
yes because your mass doesn't change but your weight can
ex- if you travel to Saturn your weight would change but your mass would stay the same
 
        
             
        
        
        
Answer:
a. 
b. 
Explanation:
a) 
F= 120,000N
Kinetic energy @ impact = 120,000*depth
 


b) 
The momentum is equal to the impulse on him from the snow so:



 
        
             
        
        
        
Answer:
Explanation:
a ) Conservation of momentum is followed 
m₁ v₁  = m₂ v₂
3m x 2 = m  v
v = 6 m/s 
Total kinetic energy 
= 1/2 x .35 x 6 ² + 1/2 x 1.05 x 2 ²
 = 8.4 J
This energy must be stored as elastic energy in the spring which was released as kinetic energy on burning the cord. 
Yes , the conservation of momentum will be followed  in the bursting apart process. Only internal forces have been involved in the process. Two equal and opposite internal forces are created by spring which creates motion and generates kinetic energy.