2 hard science questions.?

Question

1. The combustion of a fuel provides 15 000 J of thermal energy to heat water. If the temperature of 0.50 kg of water is raised by 4.0°C, calculate the efficiency of the process.

2. For each of the following energy converters, name the type or types of energy that we would consider useful:

a) Jet airplane –

b) Television set –

c) Coffee pot –

d) Toaster –

e) You –

thanks!

Answer 1

heat capacity of water: ~4.18 J/(g*K), so to heat 500g of water by 4°C we need 500*4*4.18 J=8360J

but we used 15000J which leads us to a efficiency of 8360/15000=55.73%

Answer 2

i give up. cant **** with science!

Answer 3

no no no, im all the science anyone can handle