In general momentum is defined as the product of mass and velocity. It is expressed as momentum (P) = mass ( m in Kgs) *velocity ( v in m/s) ie P = m * v kgm/s 
 Given : 
 Two objects of same size and shape a and b 
 The velocity of the both the bodies are same ie velocity =v1 = v2=v -eqn 1 But they differ in heaviness as follows : 
 The heaviness of the object a is two times of b 
 ie a =2b or a/b = 2 or a : b = 2 : 1 
 mass of the body m1= 2a --eqn-2 
 momentum of the body is a (P1)= 2m1* v 
 mass of the body m2= b --eqn 3 
 momentum of the body b (P2) = m1 * v 
 the momentum of the two bodies are P1 = P2 
 ie m1*v1 = m2*v2 
 P1 : P2 = m1*v1 : m2 * v2 
 sub the value of v2,v1 from eqn 1, m1=2a, m2=b
 P1 : P2 = 2av : bv 
 P1 : P2 = 2a : b 
 ie (P1/P2)= (2a/b) -- eqn 4
 Ans :-
 from the above eqn 4 -it is obvious the momentum of body a is twice of body b 
 ie momentum of the body a is greater.