20. The model of the universe that suggests that the sun is the center of the universe was first brought by

A. Copernicus.

B. Brahe.

C. Ptolemy.

D. Kepler.

About half of the electricity in the united states is generated using coal. true or false

The total energy of all the particles in a substance is called a. temperature. b. thermal energy. c. degrees. d. mass.

Propane (C3H8combines with oxygen gas (O2to form carbon dioxide (CO2and water (H2O). Describe the number and type of atoms for a molecule of each substance.

How many protons, neutrons, and electrons are in oxygen?

When a circular plate of metal is heated in an oven, its radius increases at a rate of 0.01 cm divided by min. At what rate is the plate's area increasing when the radius is 41 cm?

Identify the following as a suspension or a colloid. sand in water

A cyclist starts at a position of 0 m and takes 3 s to move east to a position of + 8 m. He then cycles west to a position of + 5 m which takes an additional 2 s. What is the cyclist's displacement? a. + 11mb. - 8mc. - 5m d. + 5m

What happens when you shoot a bullet into the sky?

If you want to lift a 5-kg box to a height of 2 meters, how much work must be done? O A. 2J O B. 50 J O C. 98 J O D. 100

A diver initially moving horizontally with speed v dives dives offthe edge of a vertical cliff and lands in the water a distance dfrom the base of the cliff.