Given: Mass of body $(m) = 5\, kg$ ; Height of the body $(h) = 10 \,m$ and force $(F) = 170 \,N.$
We know that work done by the force $= F \times h = 170 \times 10 = 1700\, J $ and potential energy $= mgh = 5\times 10 \times 10 = 500\, J$.
Now kinetic energy of the body (K.E.) $= 1700 - 500 =1200 \,J.$
Therefore if the velocity of the body is v, then kinetic energy $1200 = \frac{1}{2} mv^{2} =\frac{1}{2} \times 5 \times v^{2}$ or
$v^{2} = \frac{1200\times2}{5}=480$ or $v = \sqrt{480} \,≅\, 22 \,m/s$.