Physics students study a piano being pulled across a room on a rug. They know that when it is at rest, it experiences a gravitational force of 2200 N. When it is being pulled with 1200 N it is sliding across the room in equilibrium, but the students feel like they had to pull harder than 1200 N at first to begin motion. Which best describes the friction acting on the piano? The static and kinetic frictional forces are equal, so the static frictional force is equal to 1200 N. The kinetic frictional force is greater than the static frictional force, so the kinetic frictional force is greater than 1200 N. The static frictional force is greater than the kinetic frictional force, so the static frictional force is greater than 1200 N. The static and kinetic friction are both equal to the gravitational force of 2200 N.

What type of electromagnetic wave is used in security pens? a. x-rays c. microwaves b. visible light d. ultraviolet radiation select the best answer from the choices provided

Need asap ! what is the relationship between atmospheric pressure and the density of gas particles in an area of increasing pressure? (2 points) as air pressure in an area increases, the density of the gas particles in that area decreases. as air pressure in an area increases, the density of the gas particles in that area increases. as air pressure in an area increases, the density of the gas particles in that area remains constant. as air pressure in an area increases, the density of the gas particles in that area increases and decreases in an alternating pattern. 3. which of the following correctly describes a way in which earth's atmosphere interacts with the geosphere? (2 points) it contains gases that living organisms breathe. it contains gases that trap incoming solar radiation. it provides a medium for cycles that provide nutrients to living organisms. it provides a medium for water to move between earth's surface and the air. 4. which of the following is considered a drawback to using wind energy as a source of power? (2 points) wind energy is nonrenewable. wind energy produces large amounts of air pollution. 5. a meteorologist predicts that the weather in a region will soon change from clear skies to probable thunderstorms. prior to making this prediction, what did the meteorologist most likely observe on a barometer? (2 points) the barometer fell slightly. the barometer fell substantially. the barometer rose slightly. the barometer rose substantially. 6. which of the following do meteorologists not typically use weather balloons to record? (2 points) atmospheric pressure cloud types humidity temperature 7. during which step in the can crush lab did water vapor force air from the can? (2 points) the can was filled nearly to the top with water. the can was placed on the hot stove top burner for several minutes. the can was removed from the hot stove top burner. the can was placed upside-down in the water-filled pan.

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island