What is the percentage efficiency of the boat A boat motoring across a lake transforms 1600 J of chemical energy in its fuel into 950 J heat 250 J of sound 400 J kinetic.?

Answer 1

You need to divide the kinetic energy by the energy used (i.e., by the chemical energy), and convert that into a percentage.Note that in practice, normally you would use units of power (such as watts, equal to joules/second) rather than energy (such as joules).

Answer 2

The total energy output of the boat is 950 J (heat) + 250 J (sound) + 400 J (kinetic) = 1600 J. The efficiency is calculated by dividing the desired output energy by the total input energy, so the efficiency of the boat would be (950 J + 250 J + 400 J) / 1600 J = 100%.

Answer 3

If all the heat is waste, then the efficiency is 25%.