Question 1. Do humans swim slower in syrup than in water?

Answer: Not significantly. Cussler found little difference; some swimmers slowed about 4% in the guar thickened pool water.
Cussler explained that while a swimmer experiences more "viscous drag" (friction from movement through the fluid) as the water gets thicker, he generates more forwards force from every stroke. The two effects almost cancel each other out. However, below a certain threshold of speed and size, viscous drag becomes the dominant force, making syrupy fluids more difficult to swim through. Had Cussler done his experiment on swimming bacteria instead of humans, he would have recorded much slower times in syrup than in water.

The journal that published Cussler's study was the American Institute of Chemical Engineers Journal

Question 2. Which one of Newton's three laws of motion explains why some people can swim faster than others?

Answer: Newton's Second Law of Motion states that the force of an object is equal to its mass times its acceleration. (Force=Mass x Acceleration   or   F=MA) and this explains why some people can swim faster than others. For example, if two people having the same mass push off the side of the pool and do not take any strokes, the person who uses the most force pushing off the wall goes farther. Acceleration in this case is greater for the person who produced the greater force.