Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases. With more surfaces exposed, there are more places for chemical weathering to occur. Let’s say you wanted to make some hot chocolate on a cold day. It would be hard to get a big chunk of chocolate to dissolve in your milk or hot water. Maybe you could make hot chocolate from some smaller pieces like chocolate chips, but it is much easier to add a powder to your milk. This is because the smaller the pieces are, the more surface area they have. Smaller pieces dissolve more easily.
Beth, Jane and Ann were making chocolate eggs for their churches Easter sale. They decided to make three batches s of chocolate coating. They all started with a chunk of chocolate that needed to be melted in a double boiler.  Beth and Jane grated their chocolate first. Ann just threw the hole chunk into the double boiler. Beth stirred her chocolate while Jane and Ann let their melt on it's own.
Will Beth or Ann's chocolate melt faster?