An Investigative Case-Based Problem Space on Density
By Tiah Tao Koon, Ivan Ang, Ng Kuan Zhang, Henry Ng, Rosalind Ho & Ilysa Saari
What goes up? What comes down?
Sam and Michael were having lunch in the school canteen. They were discussing about the
flotation tank therapy which they had read in the newspaper.
Sam commented, “It will be great if the flotation tank can help to alleviate stress, depression,
anxiety and even chronic pain.”
Michael responded, “You are right! Imagine there will be no more visits to the doctors for
treatment, just lie in the tank and get cured!”
Sam wondered, “But I wonder why people can simply just float in the tank containing water with
a high density of Epsom Salt and don’t get drowned?”
Michael added, “I heard we can experience the life of an astronaut!”
“Why is this so?” asked Sam.
“Well, the salty water allows the person to float, and because the air and water is heated to same
temperature as the body, the sensation of water or air on the skin is greatly reduced giving the
impression that you are effortlessly floating in nothingness,” explained Michael.
The Case Narrative, with Title
What goes up? What comes down?
Case Analysis
Know / Want to know chart
Learning Goals
Pupils will be able to apply concept of density to floating and sinking.
Pupils will be able to formulate and investigate a simple hypothesis.
Misconceptions to Address
1. 1 kg of wood will sink in water but a 5 cents coin will float in water.
2. Larger volume of matter will sink.
Investigations and Activities, including cyberlearning resources
Suggested Online resources (Any two)
a) Simulation on Density
http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
b) Simulation on Buoyancy
http://phet.colorado.edu/en/simulation/buoyancy
c) Dead Sea
http://www.extremescience.com/zoom/index.php/earth-records/37-dead-sea
Suggested Experiment (Any one)
a) Virtual experimentation of floatation using simulation.
b) Hands-on experimentation with coke and diet coke in a tank of water.
Student Products
Know-Want to Know chart
Poster
Experimental designs
Magic tricks involving Density
Assessment
Rubrics on their investigations, presentation

Civic Literacy, Global Awareness & Cross-cultural Skills
Know about Dead Sea, culture of Jordan, product knowledge on Coke

Critical and Inventive Thinking
Experimentation, Know Want to Know Chart
Information and Communication Skills
Search online, management of information, responsible use of information, communicate
effectively in poster presentation, knowledge and use of ICT tools
