Two particles move about each other in circular orbits under the influence of gravitational forces, with a period τ. their motion is suddenly stopped at a given instant of time, and they are then released and allowed to fall into each other. prove that they collide after a time τ/(4 2).

Answer quickly (15 points) a comet is approaching earth. describe earth’s gravitational pull as the comet gets closer to it. a. remain constant b. increase c. decrease d. reversed

Which of the following is not a part of the respiratory system? a. pharynx b. trachea c. pancreas d. larynx hurrim timed

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.