The half-life of carbon-14 is 5730 years. explain how to figure out the age of a substance that has 25% carbon-14 remaining. a) multiply 25% times 5730 years since only 25% of the carbon remains. b) divide 5730 years by 2 since carbon has gone through two half-lives. c) multiply 5730 years by 2 since two half-lives have gone by for carbon. d) multiply 4 times 5730 years since carbon has gone through 4 half-lives.

Two horizontal plates with infinite length and width are separated by a distance h in the z direction. the bottom plate is moving at a velocity u. the incompressible fluid trapped between the plates is moving in the positive x-direction with the bottom plate. align gravity with positive z. assume that the flow is fully-developed and laminar. if the systems operates at steady state and the pressure gradient in x-direction can be ignored, do the following: 1. sketch your system 2. identify the coordinate system to be used. 3. show your coordinates and origin point on the sketch. list all your assumptions. 5. apply the continuity equation to your system. nts of navier stokes equations of choice to your system 7. solve the resulting differential equation to obtain the velocity profile within the system make sure to list your boundary conditions. check units of velocity 8. describe the velocity profile you obtain using engineering terminology. sketch that on the same sketch you provided in (1). 9. obtain the equation that describes the volumetric flow rate in the system. check the units.