Question

Forms of energy. Which is greater, the kinetic energy of a 1700 kg car moving at 100 km/hr, or a candy bar with 200 Cal (1 food Cal = 1 kcal)?

Please Explain, Thank You!

Answer 1

velocity = 100 x 1000 m / 3600 sec = 27.78 m / sec

kinetic energy (KE) = 1/2 m v^2

                                  = 1/2 x 1700 x (27.78)^2

                                 = 655864.2 J

candy bar = 200 cal

                 = 200 x 4.184 J

                 = 836.8 J

so more enrgy for the kinetic energy of a 1700 kg car moving at 100 km/hr