Tommy was walking at a rate of 4 miles per hour at noon and at 12: 30 pm he was walking at a brisk rate of 6 miles per hour. two hours later tommy was walking at a leisurely rate of 2 miles per hour. what was tommy’s acceleration between noon and 12: 30 pm?

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Utah's great salt lake has an average salinity seven times higher than that of the oceans. very few multicellular organisms live in this harsh environment. an example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. these brine shrimp must available hint(s)utah's great salt lake has an average salinity seven times higher than that of the oceans. very few multicellular organisms live in this harsh environment. an example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. these brine shrimp must pump water back into their cells to counter its loss due to osmosisactively pump water back out of their cells to counter its inflow due to osmosissynthesize membranes that are impermeable to substances that upset osmotic balanceactively pump salt back out of their cells to counter its inflow due to osmosis

What is friction? how does it affect the motion of an object?