To demonstrate that the rules for significant-figure propagation in multiplication do give an estimate of the uncertainty in the answer, consider a block with rectangular sides whose dimensions have been measured with a millimeter ruler. height: 254.7 mm width: 136.8 mm depth: 25.3 mma) determine the volume of the block in cubic millimeters. b) determine the volume of the block if you assume that each of the foregoing measurements is actually 0.1 mm too low. c) with which digit do the answers to parts a and b begin to differ? if you report the volume using all of the digits that are the same in parts a and b plus one more digit where the two values do not agree, how many digits should you report? d) how many digits would you report according to the rules for significant figures? is this the same as in part c?

Atown is considering building a biodiesel power plant that would burn biomass to generate electricity. which of the following correctly lists an advantage and a disadvantage of this project?

Moon effect. some people believe that the moon controls their activities. if the moon moves from being directly on the opposite side of earth from you to being directly overhead, by what percentage does (a) the moon's gravitational pull on you increase and (b) your weight (as measured on a scale) decrease? assume that the earth–moon (center-to-center) distance is 3.82 × 10^8 m, earth's radius is 6.37 × 10^6 m, moon's mass is 7.36 × 10^22 kg, and earth's mass is 5.98 × 10^24 kg.

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.