Answer:
 option C
Explanation:
The correct answer is option C                         
There is no external force acting in the system hence the momentum will be conserved.                                     
As the milk is leaking out of the tank mass of the tanker is decreasing.
When the mass of the container will decrease to  conservation the momentum speed of the container will have to be increased.
So, the car carrying milk will speed up.
 
        
             
        
        
        
Answer:
No, it is not necessary for them to have same mass.
Explanation:
Let both bodies have a density d1 and d2 respectively.
Since their volumes are equal V1 = V2
we know that, https://tex.z-dn.net/?f=%5Cfrac%7Bmass%7D%7Bvolume%7D
Hence, d1 =  and d2 =    
Taking the ratio of densities,we get
This implies that unless the bodies have same densities, the mass of the two bodies will not be same.
 
        
             
        
        
        
Answer:
The general equation for conservation of momentum during a collision between n number of objects is given as: [m i ×v i a ] = [m i ×v i b ] Where m i is the mass of object i , v i a is the velocity of object i before the collision, and v i b is the velocity of object i after the collision.
Explanation:
 
        
             
        
        
        
It's 12.1 m/s, assuming that's the launch velocity that's given.
For projectile motion, velocity's y-component is parabolic/quadratic. It's x-component is constant, so you don't need to know it. 
        
             
        
        
        
Force = mass x acceleration 
15 = mass x 4 
Mass = 15/4 
Mass = 3.75 Kg