Write and simplify the general energy balance for these open systems. Clearly state/draw where inlet point and outlet point are in your system (this will affect your answer). State if heat and shaft work are positive or negative (if non-zero).

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.