A rotating uniform cylindrical platform of mass 220 kg and radius 5.5 slows down from 3.8 rev/s to rest in 16s when the driving motor is disconnected. Estimate the power output of the motor required to maintain a steady speed of 3.8rev/s.

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

This is one type of line graph in which the independent variable is time plotted on the x axis and the dependent variable, also numerical, is plotted on the y axis.

How can a cyclist's acceleration change even if its velocity remains constant?