Which of the following is the best example of mechanical/physical weathering? question 17 options: the cracking of rock caused by the freezing and thawing of water the transportation of sediment in a stream the wearing of way of rock due to acid rain the formation of a sandbar along the side of a stream

The oldest rocks in the south atlantic ocean, immediately adjacent to the african and south american continental shelves, are 120,000,000 years old (time). calculate the average rate of seafloorspreading for the south atlantic ocean over its entire existence (hint: use formula: velocity = distance/time): /yr (velocity). now convert that to: cm/yr: