I need help with these questions; I'm stumped.

1#

A block in the shape of a rectangular solid has a cross-sectional area of 5.04 cm2 across its width, a front-to-rear length of 22.3 cm. and a resistance of 974 Q. The block's material contains 7.23 X 1022 conduction electronsfm3. A potential difference of 38.1 V is maintained between its front and rear faces. [a] What is the current in the block? [b] If the current density is uniform, what is its magnitude? What are {c} the drift velocity of the conduction electrons and {d} the magnitude ofthe electric field in the block? {a} Number n Units V [b] Number Units V [c] Number n Units V {d} Number Units V How long (hours) do electron5 take to move through a cable of length 9.40 m? There are 8.49 X 1023 conduction electronS per cubic meter. The current is 30.0 A. The crossSectional area is 2.50 x 10': m2. 0 10? O 8.87 O 9.49 O 4.32 O 161 O 29.6 D 67.9 C 29.8 C 12.3 0 51.5