Alex throws a 0.15-kg rubber ball down onto the floor. the ball's speed just before impact is 6.5 m/s and just after is 3.5 m/s. what is the change in the magnitude of the ball's momentum? a. 0.09 kg*m/s b.1.5 kg*m/s c. 4.3 kg*m/s d. 4.3 kg*m/s

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.