A car of mass 775 kg traveling at a velocity of 30 m/s in the positive x-direction crashes into the rear of a truck of mass 1,475 kg that is at rest and in neutral at an intersection. If the collision is inelastic and the truck moves forward at 11.9 m/s, what is the velocity of the car after the collision? (Indicate the direction with the sign of your answer. Assume the collision is head-on so that the motion of both vehicles remains entirely along the x-direction)

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.