Steel balls 12 mm in diameter are annealed by heating to 1150 K and then slowly cooling to 400 K in an air environment for which T 325 K and h 20 W/m2 K. Assuming the properties of the steel to be k 40 W/mK, 7800 kg/m3 , and c 600 J/kg K, estimate the time required for the cooling process.

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

Which notation is used to represent an alpha particle? a. b. c. d.

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.