In an episode of Tom and Jerry from 1948, Tom once again has his face smashed in from a falling object. This time, the offender was a half-ounce canary wielding circular cage parts. The bird unfastened the cage bottom and let it drop onto the unsuspecting feline below, making Tom's face into a pancake. How much force does this pan actually make? Could it really damage a cat's face?
First, we must find the velocity of the pan when it hits Tom's face. We know that the pan falls from rest, its acceleration is 9.81 m/s2, and the time it takes to fall from the cage to Tom is roughly 3 seconds (1:09 -1:12 in the youtube video). Using the equation Vf = Vi + at, we find that the velocity of the pan just before it comes into contact with Tom's face is 29.43 m/s.
Let's estimate that the pan weighs roughly .1 kg (100 g). Also, let's estimate that the time it takes the plate to go from its initial velocity just before coming into contact with Tom's face and the time when it's final velocity reaches 0 m/s is roughly 1 tenth of a second (.1 s). We know that momentum is conserved in this situation and that (Force)(change in Time) = (mass)(change in velocity). Using this, we know that the change in velocity is -29.43 m/s, so the force of the pan on Tom is roughly 30 newtons. This is equal to roughly 6.7 lb of force.
It takes anywhere from 7 to 9 lb of force to break a human nose, so even though it's not likely that the bird cage would've smashed the kitty's face in, he might very well lose his sense of smell.
Here's a blast from the past composed of 40 % physics and 60% pain. Disclaimer: I do not promote domestic animal abuse, nor do I reccomend testing 7 lbs of force on your friend's nose.