The current through a 20.0-mH inductor is LaTeX: i(t)=8t\exp(-t/5) i ( t ) = 8 t exp ⁡ ( − t / 5 ) for LaTeX: t\geq0 t ≥ 0 , where LaTeX: t t is given in seconds and LaTeX: i(t) i ( t ) is given in mA. What is the magnitude of the induced emf across the inductor when LaTeX: t=3.0~\mathrm{s} t = 3.0 s ?

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.

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

Aplate clutch has a single pair of mating friction surfaces 250-mm od by 175-mm id. the mean value of the coefficient of friction is 0.30, and the actuating force is 4 kn. a) find the maximum pressure and the torque capacity using the uniform-wear model. b) find the maximum pressure and the torque capacity using the uniform-pressure model.