7. can you make the work output of a machine greater than the work input?
no, work output is always less than work input
yes, by increasing the input force
yes, by decreasing friction
ono, work input and work output are always equal

Which type of electromagnetic waves are dangerous enough to be used to kill cancerous cells? (a)gamma rays (b)visible light (c)infrared light (d)microwaves

Which configuration would produce an electric current? a) rotate a coil of copper wire between two magnets. b) connect a wire between a copper and zinc strip sitting in a beaker of water. c) connect a wire to the (+) positive end of a battery and the other end to a light bulb. d) connect a wire to the negative end of a battery and the other end to a light bulb.

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b.refraction c.diffraction d. interference