A heat engine exhausts 8900 j of heat while performing 2800 j of useful work. part a what is the efficiency of this engine?

Describe the arrangement, motion, and energy of the molecules in the solid, liquid, and gas phases of water.

Which is a drawback to the extensive use of solar energy? A. It is nonrenewable and usually unavailable at night. B. It produces toxic pollution. C. It requires equipment and installation that are expensive. D. It is available only at night.

Explain how a step-down transformer makes electricity safe for use in homes.

Technician A says that when checking a voltage drop across an open switch, a measurement of 12 volts means the circuit is open.

Which is an unintended consequence of the widespread use of pesticides on corn crops?

In July 2005, NASA's "Deep Impact" mission crashed a 372-kg probe directly onto the surface of the comet Tempel 1, hitting the surface at 37,000 km/h.

What conversion factor is needed to change from kilometres to meters

What does the law of universal gravitation state?

Estimate the smallest possible period of a satellite in a circular orbit around earth. (mass and radius of earth is 5.98 x 1024 kg and 6.37 x 106 m. the universal gravitational constant g = 6.67 x 10-11 n. m2/kg2.)

What happens along a stationary front? a. Cold air rises over warm air. b. The flow of air is neither toward the warm air mass nor toward the cold air mass. c. Air moves so rapidly upward that hurricanes form. d. Wind stops completely.