Lawn tennis matches are often interrupted by rain. Waterproof mulch is not always effective, so the competition can only continue when the top layer of the lawn is sufficiently dry. After the rain stopped, some rainwater directly penetrated into the ground and some evaporated into the air. Some mechanical devices can be used to speed up the drying process, but in order to avoid damaging the grass, it is best to let the grass dry naturally. Can a mathematical model be established to represent this drying process?

After a partial rain, can you predict when to resume the game? Especially when it suddenly rains, the grass mud horse is dry, and the rain speed is constant and lasts for half an hour. It is assumed that the total rainfall during this period is1.8cm..

(Please note that this is the depth, and only multiplying it by the receiving area is the volume. )

Tip: {Growth rate of rain on lawn} = {Input speed}-{Output speed}

Is this it?