Answer
After the force ends, the object's speed is 3.0 m/s to the right.
Work Step by Step
We can use the graph to find the impulse exerted on the object. The impulse is equal to the area under the force versus time graph.
$J = F~t$
$J = (8~N)(0.5~s)$
$J = 4.0~N~s$
We can use the impulse to find the final momentum $p_f$.
$p_f = p_0+J$
$p_f = m~v_0+J$
$p_f = (2.0~kg)(1.0~m/s)+4.0~N~s$
$p_f = 6.0~N~s$
We can find the velocity $v_f$ after the force ends.
$m~v_f = p_f$
$v_f = \frac{p_f}{m}$
$v_f = \frac{6.0~N~s}{2.0~kg}$
$v_f = 3.0~m/s$
After the force ends, the object's speed is 3.0 m/s to the right.