A 500 kg dragster reaches a speed of 100 m/s on level ground, starting from rest. Its efficiency is only 8.00% in producing kinetic energy, because of friction and its design for high power without regard to efficiency.
(a) How many gallons of fuel does it use during this acceleration, given there are 1.30 multiplied by 108 J of energy per gallon?
(b) How much waste heat is produced?
(c) Once it is brought back to rest (assuming the engine shuts off at the end of the race), how much waste heat has been produced?
Someone help me to solve the problem.Please give me the steps.Thank you very much.
2 answers
Eric/Alice/Amy -- please use the same name for your posts.
KE of dragster: 1/2 m v^2 solve that.
Energy input=KEdragster/.080
energy input=1.30*108J*volume
set them equal, solve for volume
waste heat=energy input-KE or
waste heat=energy input*.92
Energy input=KEdragster/.080
energy input=1.30*108J*volume
set them equal, solve for volume
waste heat=energy input-KE or
waste heat=energy input*.92
1 answer