) A 6.50 kg rock starting from rest free-falls through a distance of 30.0 m. a. Assuming no air resistance, find the amount of momentum that is transferred from the rock to earth as it collides with earth’s surface in a perfectly inelastic collision. b. What is the change in velocity of earth as a result of this momentum change? The earth’s mass is 5.972 x 10^24 kg. Show all your work, assuming the rock–earth system is closed.

What is the speed of an object at a given moment?

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.

Energy flows from the producer level to the level. is called