1. M ASS AND D ENSITY - FLOAT OR SINK ?

2. O BJECTIVE S Design a “diver” that stays fully-submerged in water(but not sink to the bottom of the tank).

3. A PPARATUS Fish tank 2x pendulum bobs 5x marbles 200cm 3 measuring cylinder blue-tack Electronic balance 2x plastic container with cap

4. P ROCEDURE Step 1 Measure the volume and mass of the water in a plastic container.

5. P ROCEDURE Step 2 Measure the mass of the marbles and pendulum bobs http://www.clipartoday.com/clipart/cartoons/cartoon/cartoon_189 968.html

6. P ROCEDURE Step 3 ensure the density of the combination of the marbles, blue-tack and bobs is the same as the water

7. Step 4 Test to verify the results P ROCEDURE

8. C ALCULATIONS Density of water in container: mass/volume= 60.1/60=1.002 Calculations Mass of marbles /g 1marbl e 2marbl es 3marbl es 4marbl es 5marbl es 4.99.915.220.826.0 Mass of pendulum bobs/g 1 pendulum bob2 pendulum bob 27.856.6

9. C ONCLUSION With a combination of some blue-tack, 2 marbles and a bob, we managed to keep the “diver” suspended half way in water.

10. C ONCLUSION This involved calculating the density of the marbles, bob and blue- tack, as well as the water in the small container