A block in the shape of a rectangular solid has a cross-sectional area of 5.24 cm2 across its width, a front-to-rear length of 15.7 cm, and a resistance of 977 Ω. The block's material contains 4.45 × 1022 conduction electrons/m3. A potential difference of 39.9 V is maintained between its front and rear faces. (a) What is the current in the block