Denver constructs an electric bell as shown in the diagram below. He then turns the switch on to test the bell. Denver notices that the hammer moves a bit toward the gong, but does not quite reach the gong. Which of the following should Denver do to best increase the chances of making the bell ring?
A.
increase the length of the arm supporting the hammer and use a heavier hammer
B.
increase the current produced by the battery and the number of coils around the electromagnet
C.
decrease the size of the gong and use a larger hammer
D.
decrease the size of the gong and the number of coils around the electromagnet

If one fission reaction of a uranium-235 atom produced two neutrons, how many neutrons would be released if the chain reaction occurred three more times?

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.

What is dhmo? hint: you find it everywhere something is wet..