Agrata Singh
Last Activity: 6 Years ago
i and j represent the unit vectors in positive X and Y dirxn respectively in the solution below
Let the masses be m1 m2 m3 such that m1=m2=0.5/4=m and m3=0.5/2=2m
Let velocity of m1 be v1=v i ,of m2 be v2=v j of m3 be v3
Conservation of linear momentum gives
0=m1v1+m2v2+m3v3
0=mv i + mv j + 2mv3
v3=-1/2(v i + v j)
|v3|=1/2v (√2)=v/√2
Now writing energies of the particles
E1=E2=1/2mv2
E3=1/2x2mx(v3)2= ½ mv2
Hence E1=E2=E3
Regarding the third option v3 does make an angle of 135 with the smaller mass velocities. You can see that from the vector relationship
Hence the correct answer is (A)(C)