According to Ptolemy's model of the movement of celestial bodies, A. the sun is the center of the universe. B. the earth rotates around the moon. C. planets orbit in circular paths around the earth. D. the earth rotates around the sun.

The elements in group 17 of the periodic table are called halogens. all halogens have the same?

A 20-kg barrel is rolled up a 20-m ramp to the back of a truck whose floor is 5.0 m above the ground. What work is done in loading one barrel into the truck?

A proton and an electron are released from rest, with only the electrostatic force acting. Which of the following statements must be true about them as they move toward each other? (There could be more than one correct choice.) Check all that apply.

How to find out if used car mileage is accurate?

Assume that the temperature, 40C, and volume of the gas, 6 liters, remain constant. At 2 atmosphere of pressure, there are 0.036 moles of the gas. Write an equation that describes the pressure on the gas in terms of the amount of gas.

A gate in an irrigation canal is constructed in the form of a trapezoid 2 m wide at the bottom, 38 m wide at the top, and 2 m high. It is placed vertically in the canal so that the water just covers the gate.

A machine with a mechanical advantage of 10 is used to produce an output force of 250 newtons. What input force is applied to this machine

Why do you float in space

How does physical change affect the identity of a substance

A scientist pours grape juice on three identical white shirts He then uses three different cleaning products on the shirts and measures how clean they get what is the independent variable in this experiment