Abulldozer drags a log weighing 500 n along a rough surface. the cable attached to the log makes an angle of 30 degrees with the ground. the coefficient of static friction between the log and the ground is 0.500. what is the minimum tension required in the cable in order for the log to begin to move?

Students in an introductory physics lab are performing an experiment with a parallel-plate capacitor made of two circular aluminum plates, each 11 cm in diameter, separated by 1.0 cm. how much charge can be added to each of the plates before a spark jumps between the two plates? for such flat electrodes, assume that value of 3×106n/c of the field causes a spark.