(20 13? Wenzhou Waterfront Pavilion is an ornamental dragon boat. (1) The dragon tail of the pavilion is carved from a nanmu. Carving process

(1) Brother Tai's dragon tail is made of a nanmu. In the process of carving, the change of nanmu is a physical change.

(2) When paddling, the paddle rotates around a fixed point under the action of force, which can be regarded as a lever.

(3) Motion and stillness are relative reference objects. In the dragon boat race, if you take rowing as a reference, the houses on the shore are moving.

(4) Buoyancy F = ρ water gV row =/kloc-0 /×103kg/m3×10n/kg× 30m3 = 3×105n.

So the answer is: (1) physical change; (2) lever; (3) exercise; (4)3× 105.