5. According to the table, Approximate Coefficients of Friction, which surface would offer the greatest traction for a rubber tire? (1) dry concrete
(2) wet concrete
(3) dry asphalt
(4) wet asphalt

Proof: Explain your reasoning.

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.