You manage to organize an event where all the faculty, staff, and students at pcc gather by the mirror pools to jump upwards, as high as they can, in unison, in order to push the earth downward. make an order-of-magnitude estimate of the speed they manage to impart to the earth as a result of the synchronized jump. as always, clearly state the quantities you are estimating.

Total solidification times of three casting geometries are to be compared: a sphere, a cylinder, in which the length-to-diameter ration - 1.0, and a cube. volume = 1000 cm^3 for all three shhapes, and the same casting alloy is used. a) determine the solidification times of each geometry b) based on the results of part (a), which geometric element would make the best riser? c) if the mold constant = 3.5 min/cm^2 in chvorinov's rule, compute the total solidification time for each casting.

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

What is the measurement of how fast an object moves relative to a reference point?