What percentage of all car accidents are caused while the driver is talking on a cell phone?

a
20%

b
25%

c
40%

Air at a pressure of 1atm and a temperature of 40 c is in parallel flow over the top surface of a flat plate that is heated to a uniform temperature of 120 c. the plate has a length of 0.40m (in the flow direction) and a width of 0.15m. the reynolds number based on the plate length is 50, 000. what is the rate of heat transfer from the plate to the air? if the free stream velocity of the air is doubled and the pressure is increased to 10 atm what is the rate of heat transfer?

Apreheater involves the use of condensing steam at 100°c on the inside of a bank of tubes to heat air that enters at 1 atm and 25°c. the air moves at 5 m/s in cross flow over the tubes. each tube is 1 m long and has an outside diameter of 10 mm. what is the minimum value of nl needed to achieve an outlet temperature of t 75 c? what is the corresponding pressure drop across the tube bank?

What is the maximum height from which a mass of 30 kg can fall on to a flange on the lower end of a vertical rod of length 1.0 m and diameter 20 mm, the upper end being rigidly fixed, if the stress in the rod is not to exceed 80 mpa? the tensile modulus of the rod is 200 gpa.