Mechanical weathering is when rocks are broken down by mechanical means, and pysical weathering is the mechanical breakdown of rocks. Given these facts, what is when rocks are broken down among the following options:
- roof weathering
 - Plant growth is reduced
 - brick weathering
 - Physical weathering
 - remains of prehistoric life
 - at or near the margins
 - home weathering
 - major threat to health


 

    Physical weathering     