The problem specifies that the fluid material is water while the default assignment is air. Once inside the Physics template select Material Assignments. Under the Material drop down menu select Water (Material Samples).
Boundary Conditions / Forces
Since this problem statement only specified the lid of the box as moving, we assign a wall condition to the top face of the volume. Select the Physics task. In the Fluid Flow Conditions section, press Add > Wall and select the top face of the flow volume. In the Flow Specification, change Wall velocity from Stationary to Moving and specify the Magnitude as 1 [m s^-1], as given in the problem description. Now that the wall is moving, a direction must be specified by inputting a value in the Cartesian Direction Components. Input 1 as X while Y and Z must be zero. See below for an example.
A symmetry condition is applied to two opposing faces (shown below). Select symmetry from the Add dropdown menu and apply it to two opposing faces.
Next, a wall condition must be added to all surfaces that are not already defined. Wall can be found in the same Add menu as the previous conditions. Once the Wall condition is chosen, AIM selects every face that doesn't already have a boundary condition on it.