Trolley A has mass $9.0$ kg and is moving at $2.5$ ms$^{-1}$.

Trolley B has mass $15.0$ kg and is moving at $5.2$ ms$^{-1}$ at an angle of $65^{\circ}$ to the path of A.

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The trolleys collide and become tangled, moving off together.

Trolley A and B form an isolated system.

What is the magnitude of the component of their combined momentum along the original direction of trolley A?