Am dong test
friction causes machines to: gain energy lose energy do more work make electrical energy

When someone slams her books on a table the kinect energy is transferred into vibrations that travel to your ears as sound waves which statement describes the movement of those waves

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?