Flashcards: Stellar Energy and Measurement Fundamentals — 20 cards

Sun's surface temperature

About 5800 K / 5500°C.

Sun's core temperature

Approximately 15 million °C.

Sun's core pressure

Around 250 billion atmospheres.

Sun's main composition

75% hydrogen, 25% helium by mass.

Sun's total mass

About 2 x 10^30 kg.

Sun's diameter

Approximately 1.4 million km.

Nuclear fusion process

Nuclei combine, releasing energy.

Fusion vs chemical reactions

Fusion involves nuclei, releases more energy.

Solar system's dominant body

The Sun, with 99.9% of total mass.

Earth-Sun distance

Approximately 150 million km.

Sun's future into Red Giant

In ~5.5 billion years, diameter up to 1 billion km.

Earth's habitability timeline

Uninhabitable in ~1-1.5 billion years.

Fundamental SI unit of length

Meter (m), based on light speed.

SI unit of time

Second (s), based on cesium atom.

SI unit of mass

Kilogram (kg), based on Planck constant.

SI unit of electric charge

Coulomb (C), charge transferred by 1 A in 1 s.

SI unit of temperature

Kelvin (K), absolute zero; Celsius (°C) offset by 273.15.

Prefix 'kilo-'

Multiplier 10^3 (1,000 times).

Prefix 'milli-'

Multiplier 10^-3 (one-thousandth).

Energy content of petrol

About 33 MJ per liter.