Answer
a) Static equilibrium.
b) Dynamic equilibrium.
c) Not in equilibrium.
d) Dynamic equilibrium.
e) Not in equilibrium.
Work Step by Step
a) Since the barbell is held stationary in your hand and you are not moving your hand up or down, left or right, back or forth, and also not rotating your hand in any direction, it must be is static equilibrium.$$\color{green}{\bf\text{The barbell is in static equilibrium.}}$$
b) The girder here is moving upward at a constant velocity which means that the net force exerted on the girder is zero.
$$\color{blue}{\bf\text{The girder is in dynamic equilibrium.}}$$
c) The girder here is moving downward while slowing down. This means that the net force exerted on it is not zero at all.
$$\color{red}{\bf\text{The girder is not in equilibrium.}}$$
d) The jet plane here is moving at a constant velocity which means the net force exerted on it is zero.
$$\color{blue}{\bf\text{The jet plane is in dynamic equilibrium.}}$$
e) The box in the back of a truck did not slide forward because of the static friction force exerted on the box backward. This means that the net force exerted on the box is not zero.
$$\color{red}{\bf\text{The box is not in equilibrium.}}$$