The weather is warm and dry what changes would a cold front bring

The pressure, volume, and temperature of a mole of an ideal gas are related by the equation pv = 8.31t, where p is measured in kilopascals, v in liters, and t in kelvins. use differentials to find the approximate change in the pressure if the volume increases from 14 l to 14.6 l and the temperature decreases from 375 k to 370 k. (round the answer to two decimal places.)

If anyone who can me with this hw? i would really appreciate it

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.