PLEASE HELP ME BECAUSE I DON'T HAVE LONG TIME TO REVIEW: how to determine the magnetic induction vector caused by a current element at a point ???

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.

Increasing the pressure on one spot of a fluid will increase the pressure everywhere else in the fluid a. pascals principal b. archimedes' principal c. bernoulli's principal

What is the single most important equation in all of physics?