My answer is "yes" for four reasons;
Wording: a physical block is not animate and it definitely isn't a creature. So something that breaks inanimate objects should work on it
A physical block, in general, as the game term, while not being animate, is not an object. It is a circumstance, or set of circumstances, that
might include an object.
Consistency: strength powers can already be used to break physical blocks - such as walls, doors and buildings. There's even a chart assigning block strength to such objects. So there's no reason they should not be used against other forms of physical blocks.
and thus, 'maybe', depending on circumstances, when appropriate
Balance: wizards are strong already while melee fighters are mechanically weaker. Allowing it redresses that problem.
Flavor: if you don't allow it, a human boxing champ hitting with his fists (superb skill) has a better chance of breaking a physical block than a black court master with supernatural strength hitting with his claws (great skill) even though the black court master's blows are more physically powerful than a rocket launcher. Since we are talking about a wizard making a block against physical force this doesn't make sense.
A character with great skill and supernatural strength defends against a grapple, a particular form of physical block, at superb. This is because the strength powers do not impart additional mass, nor necessarily the skill with which to use the imparted strength - proper leverage, anticipation, and response can still be of great significance. For other forms of 'physical block', this may vary, and rightly so. Immense strength will do you no good against a block created by a wall of supernaturally intense flame or a hail of bullets, but would be particularly effective against a 'block' created by being bound in ropes or chains.
Seeing as there are four fairly solid reasons for a "yes", I am allowing it in my games.
There are situations when the lifting/breaking modifiers would likely be appropriate, but I would urge caution in applying them too freely.