To find the work done on the object being dragged at a constant velocity, we need to consider the forces acting on it.

1. Weight of the object (W):
   $W = m \cdot g = 10 \, \text{kg} \cdot 9.81 \, \text{m/s}^2 = 98.1 \, \text{N}$

2. Normal force (N):
   The vertical component of the pulling force affects the normal force. The normal force is given by:
   $N = W - F_{y} = W - (F \cdot \sin \theta)$
   where $F$ is the pulling force, and $\theta$ is the angle.

3. Frictional force (F_f):
   $F_f = \mu \cdot N$
   where $\mu = 0.2$.

4. Force required to overcome friction:
   Since the object moves at constant velocity, the horizontal pulling force equals the frictional force:
   $F \cdot \cos \theta = F_f$.

Using these relations, you can calculate the work done by the pulling force, considering the distance moved (4 m).

Let's break it down:

1. Calculate the normal force and frictional force.
2. The work done (W) by the pulling force can be calculated as:
   $W = F \cdot d \cdot \cos(0) = F \cdot d$,
   since the angle of displacement and force direction is the same.

Would you like me to perform the detailed calculations?