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.

A person lies on a platform which has a scale under both ends. imagine the scale on the left reads 575 n and the scale on the right reads 280 n. when the person gets off the platform, both scales read 70.0 n.

An electric circuit consists of a variable resistor connected to a source of constant potential difference. If the resistance of the resistor is doubled, then

Why are the transverse waves produced by an earthquake known as secondary wave?

A boat with an anchor on board floats in a swimming pool that is somewhat wider than the boat. Does the pool water level move up, move down, or remain the same if the anchor is (a) dropped into the water or (b) thrown onto the surrounding ground

An object which has a mass of 70 kg is sitting on a cliff 10m high calculate the objects potential energy. given g=10m/s^2 A. 7,000 Joules B. 3,500 Joules C. 700 Joules D. 70 Joules E. 35 Joules

1) How is chemical energy transformed into potential energy?

A double-paned window has two glass panes separated by a layer of air. Why is air, rather than glass, used to fill this space?

To determine waves frequency you must know the what

What is the average speed in miles per hour of the car that traveled a total of 200 miles in 5.5 hours

A solid weighs 277.5 g in air and 212.5 g when totally immersed in the liquid of density 0.9 g / cc. Calculate the density of the solid.