Answer:
Part a)
[tex]Q = 2.47 \times 10^6[/tex]
Part b)
t = 4950.3 s
Explanation:
As we know that heat required to raise the temperature of container and water in it is given as
[tex]Q = m_1s_2\Delta T_1 + m_2s_2\Delta T_2[/tex]
here we know that
[tex]m_1 = 0.750[/tex]
[tex]s_1 = 900[/tex]
[tex]m_2 = 2.50 kg[/tex]
[tex]s_2 = 4186[/tex]
[tex]\Delta T_1 = \Delta T_2 = 100 - 30 = 70^oC[/tex]
now we have
[tex]Q_1 = 0.750(900)(70) + (2.5)(4186)(70) = 779800 J[/tex]
now heat require to boil the water
[tex]Q = mL[/tex]
here
m = 0.750 kg
[tex]L = 2.25 \times 10^6 J/kg[/tex]
now we have
[tex]Q_2 = 0.750(2.25 \times 10^6) = 1.7 \times 10^6 J[/tex]
Now total heat required is given as
[tex]Q = Q_1 + Q_2[/tex]
[tex]Q = 779800 + 1.7 \times 10^6 = 2.47 \times 10^6 J[/tex]
Part b)
Time taken to heat the water is given as
[tex]t = \frac{Q}{P}[/tex]
here we know that
power = 500 W
now we have
[tex]t = \frac{2.47 \times 10^6}{500} = 4950.3 s[/tex]
