#### Answer

After the impulse, the object's speed is 1 m/s to the left.

#### Work Step by Step

The change in momentum of an object is equal to the impulse exerted on the object. The final momentum is equal to the initial momentum plus the impulse $J$.
$p_f = p_0+J$
$p_f = m~v_0+J$
$p_f = (2~kg)(1~m/s)-4~N~s$
$p_f = -2~N~s$
We can find the final velocity of the object.
$p_f = -2~N~s$
$m~v_f = -2~N~s$
$v_f = \frac{-2~N~s}{m}$
$v_f = \frac{-2~N~s}{2~kg}$
$v_f = -1~m/s$
After the impulse, the object's speed is 1 m/s to the left.