Use spring scales to measure the buoyant force on fishing bobbers. Experiment with salt water's effects on buoyancy. Through these activities, you promote predicting, testing, and analyzing skills in all your students. At the end of the unit, you assess students' progress as a they apply what they have learned to predict and test whether cylinders made of a mystery substance will float or sink in fresh and salt water. These activities are so engaging and the sequence so logical that students gain a real sense of accomplishment with their investigative skills.
Students explore the combination of factors that influence whether an object floats or sinks.