Is a rock falling from a cliff a chemical or mechanical weathering?

Answer 1

It is a physical change.

Answer 2

Mechanical weathering can be created by:

• repeated freeze thaw cycles
  
• windblown sand or grit impacting the rock surface
  
• thermal stress frpm ssunligt
  
• impact from falling
  
• water impacting loose rocks
  
• animal or human traffic
  

Answer 3

Well actually all types of weathering break rocks into pieces, as that is what weathering is - the breaking up of rocks in situ.

So, then, I suppose that what you're after is the type of weathering which breaks rocks into fragments (like if you dropped glass, you'd get angular fragments, right?). Well, one form of weathering which breaks up rocks with this result is freeze-thaw weathering, which consists of water getting into a crack, expanding as it freezes overnight, then eventually causing the rock to fracture and break off. This may have the result you have in mind.

It's certainly one of the better known types of weathering, but they do all have the effect of breaking down the rocks, which will ultimately always have a similar effect.

Answer 4

It would increase the rate of chemical weathering due to the increase in surface area that becomes available to attack from chemical reactions.

Answer 5

This would be mechanical weathering because you are not changing the chemical composition of the rock.

Answer 6

Cold weather causing repeated freeze and thaw cycles is one way rocks are broken down into smaller pieces in mechanical weathering.

Answer 7

It is a physical change.

Answer 8

chemical