Achemist notices some silvery liquid on the floor in her lab. she wonders if someone accidentally broke a mercury thermometer, but did not thoroughly clean up the mess. she decides to find out of the silver stuff is really mercury. from her tests with the substance, she finds out that the melting point for the liquid is 275 k. a reference book says that the melting point for mercury is -38.87°c. is this substance mercury? explain your answer and show all relevant calculations.

The magnitude of the poynting vector of a planar electromagnetic wave has an average value of 0.939 w/m2 . the wave is incident upon a rectangular area, 1.5 m by 2.0 m, at right angles. how much total electromagnetic energy falls on the area during 1.0 minute

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)

You can decrease the resistance of a length of wire by