PURPOSE: To demonstrate how pressure balances gravity in the sun (a star) and why pressure increases toward the center of the star.

DESCRIPTION: This uses the syringe arrangement for the Boyle's law demonstration.

First put one or two weights on the syringe and read the pressure. This simulates gas pressure balancing gravity of overlying material in a star's outer regions. To simulate the effect of going toward the stellar center, put on more weights and read off the higher pressure resulting. A TV camera can be used to read the pressure meter.

SUGGESTIONS: Hold the boxes when you balance them so they will not fall off!

REFERENCES: (PIRA unavailable.)

EQUIPMENT: Boyle's Law syringe apparatus with holder and soft weights (boxes).

SETUP TIME: 5 min.

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