Final answer:
The 147-lb concrete canoe displaces more water than the 40-lb Kevlar canoe by the difference in their weights, which is 107 lbs. This is based on Archimedes' principle, which indicates that the buoyant force is equal to the weight of the displaced fluid.
Step-by-step explanation:
The amount of water displaced by a canoe directly relates to the canoe's weight and the weight of its load, reflecting Archimedes' principle which states that the buoyant force on an object is equal to the weight of the fluid it displaces. Given that both canoes are the same size and carry the same load, the difference in water displacement between the two canoes would be equal to the difference in their weights. The 147-lb concrete canoe would displace more water than the 40-lb Kevlar canoe by the weight difference of 107 lbs (assuming weight is equivalent to mass and using the gravitational acceleration of 9.8 m/s2 to find force). This is because a heavier canoe must displace a volume of water whose weight is equal to its own weight plus the weight of the load to stay afloat.