Answer:
134.75935 seconds
Explanation:
m = Amount of water = 240 mL
c = Specific heat of water = 4.2 J/mL °C
[tex]\Delta T[/tex] = Change in temperature = [tex]100-25=75[/tex]
t = Time taken
P = Power = 1100 W
E = Pt
Efficiency = 51 %
So, Energy = 0.51Pt
As energy is conserved
Q = 0
[tex]\\\Rightarrow -mc\Delta T+E=0\\\Rightarrow -mc\Delta T+Pt=0\\\Rightarrow -240\times 4.2(100-25)+0.51\times 1100t=0\\\Rightarrow t=\frac{240\times 4.2(100-25)}{0.51\times 1100}\\\Rightarrow t=134.75935\ s[/tex]
The it takes to raise the temperature is 134.75935 seconds
