A standard penetration test was carried out in a normally consolidated sand at 7.62 m depth where the N60 was determined to be 28. The unit weight of the sand is 17.29 kN/m3 , and the grain-size distribution suggests that D50 5 1.2 mm and Cu 5 3.2. The age of the soil since deposition is approximately 5000 years. Determine the relative density using the different correlations discussed in Section 3.15 [i. e., Eqs. (3.21), (3.22), (3.23), (3.24), and (3.28)].

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Agas mixture consists of 8 kmol of h2 and 2 kmol of n2. determine the mass of each gas and the apparent gas constant of the mixture.

An engine runs on the ideal diesel cycle. the cycle has a compression ratio of 20 and a cutoff ratio of 2. the highest temperature in the cycle is 1200 k. if the heat into the system is 300 kj/kg of working fluid and using variable specific heats determine the work produced per mass of working fluid