As we know total momentum of a system is constant according to law of conservation of momentum i.e.
![m_1v_1\text{ = m}_2v_2;](https://img.qammunity.org/2023/formulas/physics/college/vp2xxjysb1r5xl49tfu5qe19h1acwzhwi5.png)
where m indicates mass and v indicates velocity .
Now initial mass of system = 10 +2= 12 kg;
initial velocity = 2m/s ( assuming south as positive direction)
initial momentum = 12 ×2 = 24kgm/s;
Now, after jump
Final momentum = 2v - 10(-1)= 2v-10 ;
according to law
![\begin{gathered} 2v-10=\text{ 24;} \\ v=(24+10)/(2)\text{ = 17 m/s in south} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/4j1feepip1407biuui8auoi80z3kmttan3.png)
Final result is :-
velocity of the hoverboard = 17m/s in south.