How long does it take a 750-w coffeepot to bring to a boil 0.65 l of water initially at 13 ∘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∘.

353 s

Explanation:

Energy               = energy needed to raise the temperature of pot to 100°C +

required              energy needed to raise the temperature of water to 100°C

                    = MCΔT + mcΔT                      

                     = 0.65 kg * 4186 J/kg-°C * 87 °C + 0.36 kg * 900 J/kg-°C * 87 °C

                     = 264 906.3 J

Energy required = energy delivered * time

264 906.3 J = 750 J/s * time

time = 353 s

resonant frequency

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2