If a set of displacement vectors laid head to tail make a closed polygon, what is the resultant vector?

The step-down transformer gives a current of 10a at 24v if the primary voltage is 240v calculate the 1_primary current 2_the power input 3_the power output

The slope of a velocity time graph over any interval of time gives the during that interval

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.