On a hot day, you are in a sealed, insulated room. the room contains a refrigerator, operated by an electric motor. the motor does work at the rate of 352 w when it is running. the refrigerator removes heat from the food storage space at a rate of 450 w when the motor is running. in an effort to cool the room, you open the refrigerator door and let the motor run continuously. at what net rate is heat added to (+) or subtracted from (−) the room and all of its contents?

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Select the best definition for wavelength. the height of an oscillating electromagnetic wave the rate at which electromagnetic waves oscillate. the distance between two crests of an electromagnetic wave. the oscillations of electric and magnetic fields select the best definition for frequency. the oscillations of electric and magnetic fields. the height of an oscillating electromagnetic wave. the distance between two crests of an electromagnetic wave. the rate at which electromagnetic waves oscillate