If a car engine burns an equivalent of 20,000 joules of energy and attains a kinetic energy of 5,000 J, how much energy is dissipated in the form of heat?

Question

anonymous · Answer

I just don't know whether to add them or subtract them.

anonymous · Answer

$$\eta = \frac{ Eout }{ Ein } \times 100 % $$
$$\eta = \frac{ 5000 }{ 20000} \times 100 percent$$

$$\eta = 25 percent$$

anonymous · Answer

100 - 25 = 75 percent energy is dissipated in the form of heat :)

anonymous · Answer

Oh okay. So then it would be 15,000 J ? & Thank you for helping me!

anonymous · Answer

yes of course :) ur welcome

anonymous · Answer

dont forget about medal :p