one thermometer bulb is covered with a damp cloth and the instrument is waved through the air. The temperatures of both are taken and subtracted. The difference is matched to the Relative Humidity Chat
200
What is gravity?
Invisible force of attraction between two objects.
200
What is a light year?
Distance that light travels through a vacuum in one year
200
How fast can light travel around the Earth?
7 times around the Earth in one second
200
A cluster of stars, gas, and dust held together by gravity.
galaxy
300
What are air masses?
air that sits for a long period of time over land or over water and takes on the characteristics of what is underneath
300
What causes season on earth?
revolution of the earth around the sun and the rotation of the earth on its axis
300
How do stars form?
gravity pulls together gas and dust from a stellar nebula and nuclear reactions begin producing light and heat
300
What stars live the longest?
smaller stars because they don't burn as fast.
300
Type of galaxy that lacks gas and dust so new stars cannot form. These have only old stars.
Elliptical Galaxies
400
Why does earth have wind and ocean currents?
The Earth's surface is heated unequally by the sun causing the sunlight to be more concentrated at the equator and spread out at the poles. This causes temperature differences of hot air at the equator and cold at the polar regions. Convection then moves the air currents because hot air rises and cold air sinks.
400
What is absolute magnitude?
how bright a star would look if it were 32.6 light years away from other; or the true brightness of a star
400
What is the life cycle of Main Sequence Stars?
protostars, red giant, planetary nebula, white dwarf, black dwarf
400
What is an anemometer?
Measures wind speed by multiplying the circumference by the revolutions.
400
Galaxy that has a flat rotating disk with stars, gas and dust with a central concentration of stars known as the bulge. These have middle-aged stars.
Spiral Galaxies
500
How is our sun classified? (two parts)
medium-sized, main sequence
500
What causes the moon phases?
The way the moon appears to us on Earth as it revolves around the Earth
500
What are the 3 characteristics used on H-R diagrams to classify stars?