uThe carts are of equal
mass and speeds (velocities equal in magnitude)
uMomentum of
cart A = mava
uMomentum of
cart B = mbvb
uSince the
direction of travel of carts A & B is
opposite va = -vb
uTherefore, mava = -mbvb and
umava + mbvb = 0
uTotal vector
momentum = 0