Bessel's Star (61 Cygni) was the first star whose distance was calculated using the parallex method. The star is known to make an angle of 570 milliarcseconds between two opposite
points of the Earth's orbit. Using this information, calculate the distance to the star.

Yvette hangs a 2.4kg bird feeder in the middle of a rope tied between two trees. the feeder creates a tension of 480 n in each side of the the rope.

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.

9.98 kg of r-134a at 300 kpa fills a rigid container whose volume is 14 l. determine the temperature and total enthalpy in the container. the container is now heated until the pressure is 600 kpa. determine the temperature and total enthalpy when the heating is completed. use data from the steam tables.