A solar powered medical refrigerator for vaccine storage and transport uses a 12V battery as the power source. Battery capacity is given in terms of A-hr, e. g., a 20 A-hr, 12 V battery can supply 20 A of current for 1 hour at 12 volts. Once the fridge is cooled down, it requires 420 W-hrs (i. e., requires 420 W of power for 1 hr) of energy to maintain its temperature over a 24 hour period. What is the minimum battery size that would be needed to power the refrigerator for two days if there is no sun

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

F500 j of energy were added to 1 kg of each of these samples, which would experience the least temperature increase?

Aplane takes off from an airport and flies to town a, located d1 = 215 km from the airport in the direction 20.0° north of east. the plane then flies to town b, located d2 = 230 km at 30.0° west of north from town a. use graphical methods to determine the distance and direction from town b to the airport. (enter the distance in km and the direction in degrees south of west.)