If 3.0 × 10^15 electrons flow through a section of a wire of diameter 2.0 mm in 4.0 s, what is the current in the wire? (e = 1.60 × 10^-19 c)

Using the given relationship between electrons and coulombs;

1 e = 1.60*10^-19 C

Total charge = 3.0*10^15*1.6*10^-19 = 4.8*10^-4 C

Current = Coulombs/Time = (4.8*10^-4)/4 = 1.2*10^-4 C/s = 1.2*10^-4 Amps

Current in amperes, A = 0.00012 A = 0.12 mA

physical or mechanical weathering

Explanation:

Mechanical weathering which is also referred to as the physical weathering occurs when a rock is broken down into smaller pieces. In this case, there will be a physical change of the rock but its composition will not change.

Some examples include ice freezing and expansion of the cracks in the rock, Smstrong winds that carrycpieces of sand which then sandblast surfaces, moving water which causes abrasion etc.