Awave is described by the expression x = 5.0 sin [ (? /8)x + (6? )t ], where x is in meters and t is in seconds. determine:
a) the frequency,, period, wavelength & amplitude of the motion
b) the propagation speed and direction of this wave
c) the expression for the speed as a function of time
d) the expression for the acceleration as a function of time

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

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)