How long does it take a 750-w coffeepot to bring to a boil 0.85l of water initially at 15? c?

assume that the part of the pot which is heated with the water is made of 360 g of aluminum, and that no water boils away. ignore the heat loss to the surrounding environment.

the value of specific heat for water is 4186 j/kg? c? and for aluminum is 900 j/kg? c? .

Explanation:

power rating of the coffee pot,

volume of water to be boiled,

initial temperature of water,

mass of aluminium in the pot,

specific heat of aluminium,

specific heat of water,

Considering that the water and aluminium are always at the same temperature.

Now the heat required to bring the water in the pot to 100°C:

Therefore time required to boil the water:

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.