1 / 14

FLOTATION

Let’s Get Physical:. FLOTATION. AIM.

erno
Télécharger la présentation

FLOTATION

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Let’s Get Physical: FLOTATION

  2. AIM • Flotation: A piece of a flattened raisin, which is dropped into a glass of soda water, periodically sinks and goes back to the surface. Investigate the dependence of the period of these oscillations on various parameters. (Note: a combination of vinegar and bicarb of soda in water also works quite well).

  3. KEY CONCEPTS • Why does the raisin sink then float? • Higher density ∴ sinks • CO2 provides less dense medium ∴ floats • Bubbles pop, CO2 escapes so back to top

  4. KEY VARIABLES • Surface area of sultana • Kept constant (uncertain uncertainty) • Weight of sultana • Kept constant (uncertainty: 9.2%) • Size of sultana • Kept constant (uncertain uncertainty) • Amount of CO2 being released • Varied

  5. MATERIALS • 1x Glass Tube • 2x 250 mL beakers • 5x sultanas • 500 mL white vinegar • 20.37g baking (bicarbonate) soda • 1x 600g scale

  6. METHOD • 100 mLvinegar poured into tube • Soda measured out • Tube of vinegar placed on scale, weighed • Soda added • Waited 20s • Sultana added • Oscillations counted over 120s, final weight taken at end

  7. METHOD

  8. METHOD

  9. SAFETY • Lab coat & goggles optional • Basic lab rules – no running, etc. • Glassware involved • Add bicarb gradually • Prevents liquid getting on to electronic equipment

  10. DIFFICULTIES • Surface area of sultana • Kept constant (uncertain uncertainty) • Weight of sultana • Kept constant (uncertainty: 9.2%) • 0.46g ± 0.05g (avg ± st dev) • Size of sultana • Kept constant • (uncertainty)

  11. RESULTS

  12. ANALYSIS

  13. ANALYSIS Frequency = Oscillations / second Frequency = Period =

  14. CONCLUSION • Gas being released increases • Oscillations increase exponentially • Period decreases inversely • Many minute variables • Requires precise instruments

More Related