(ENEM 2020) Uma torneira está gotejando água em um balde com capacidade de 18 litros. No instante atual, o balde se encontra com ocupação de 50% de sua capacidade. A cada segundo caem 5 gotas de água da torneira, e uma gota é formada, em média, por 5times 10^-2mL de água. Quanto tempo, em hora será necessário para encher completamente o balde, partindo do instante atual? A . 2times 10^1 B 1times 10^1 C 2times 10^-2 D 1times 10^-2 E 1times 10^-3

First, we need to calculate how much water is currently in the bucket. Since the bucket is 50% full and has a capacity of 18 liters, there are currently 9 liters of water in the bucket. <br /><br />Next, we need to calculate how much water is added per second. Since each drop of water is 5x10^-2 mL and 5 drops fall per second, this means that 0.25 liters of water are added per second. <br /><br />To find out how long it will take to fill the bucket, we need to subtract the current amount of water from the total capacity and divide by the amount of water added per second. This gives us (18 - 9) / 0.25 = 36 seconds. <br /><br />However, the question asks for the answer in hours, so we need to convert 36 seconds to hours. Since there are 3600 seconds in an hour, 36 seconds is 36/3600 = 0.01 hours. <br /><br />Therefore, the time required to fill the bucket is 0.01 hours, which is equivalent to 1x10^-2 hours. So, the correct answer is D.