A207 series radial-contact ball bearing is loaded uniformly (without shock) as follows: • load is 8 kn at a speed of 1440 rev/min for 25% of the time; • load is 10 kn at a speed of 720 rev/min for 50% of the time, and • load is 20 kn at a speed of 2880 rev/min for 25% of the time. estimate the bearing life for a 90% reliability.

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?

Apressure vessel with an r/t 20 cannot be treated as thin walled vessel. a)-trune b)- false