NFPA 70E Annex F Risk Assessment and Risk Control Sections F.3 and F.4 provide insight to how design concepts and system upgrades can reduce or eliminate electrical hazards. Table F.3, The Hierarchy of Risk Control Methods, lists six Risk Control Methods; the lower the number in this table, the greater the effectiveness in reducing the risk. The design concepts and upgrades discussed pertain to (1) elimination, (2) substitution, and (3) engineering controls in the hierarchy of Table F.3. Safety by design is considered to have less effectiveness than item (6) PPE in the Hierarchy of Risk Control Methods. Select one:
True
False

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.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

Burgers vector is generally parallel to the dislocation line. a)-true b)-false