A boy is rolling a 0.5 kg ball on the frictionless floor with the speed of $20 \mathrm {~m} \mathrm {~s} ^ { - 1 }$. The ball gets deflected by an obstacle on the way. After deflection it moves with $5\%$ of its initial kinetic energy. What is the speed of the ball now?\\
(1) $19.0 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(2) $4.4 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(3) $14.41 \mathrm {~m} \mathrm {~s} ^ { - 1 }$\\
(4) $1.00 \mathrm {~m} \mathrm {~s} ^ { - 1 }$