The speed of light is 300,000 km/s, or about 671,000,000 miles per hour. Quite a few orders of magnitude larger than 90 mph.

The kinetic energy of an object depends on both its mass and its velocity. A fly against your car is light enough, and the velocity of your car is small enough, that a collision between a car and a fly does nothing to the car. Once you approach lightspeed though, even a speck of dust could wreak havoc

I went to that museum and it was awesome. IIRC there were some special circumstances that allowed the ship to be preserved extremely well (something about the salt concentration, water temperature, maybe the kind of wood used as well).