Question 1161286
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<pre>

Apply the Momentum conservation law at collision.


    {{{m*v}}} = {{{(m + M)*V}}}


m = 0.1 kilograms is the mass of ball A;

v = 10 m/s is its its velocity before colliding;

M = 0.7 kilograms is the mass of ball B;

V is unknown velocity of the merged body.


From the formula,


    V = {{{(m*v)/(m + M)}}} = {{{(0.1*10)/(0.1+0.7)}}} = 1.25 m/s.    <U>ANSWER</U>
</pre>

Solved.