Is this homebrew spell balanced?
Casting Time: 1 action
Range: Self (15-foot cone)
Components: V, S
A wave of powerful air sweeps out from you. Each creature in a 15-foot cone originating from you must make a Strength saving throw. On a failed save, a creature takes 2d8 bludgeoning damage and is pushed 10 feet away from you if a creature fails the save by 5 or more they are knocked prone.
On a successful save, the creature takes half as much damage and isn't pushed.
In addition, unsecured objects that are completely within the area of effect are automatically pushed 10 feet away from you by the spell's effect.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.