The kinetic energy of an object depends on its mass and velocity. The mass of a Toyota Prius is approximately 3,000 pounds (1,361 kilograms). The average speed of a Prius is about 45 miles per hour (72 kilometers per hour). Using the formula for kinetic energy, KE = 1/2 mv^2, we can calculate the kinetic energy of a Toyota Prius as follows:
KE = 1/2 (1361 kg) (72 km/h)^2
KE = 1/2 (1361 kg) (5184 km^2/h^2)
KE = 3,535,776 joules
Therefore, the kinetic energy of a Toyota Prius traveling at an average speed of 45 mph is approximately 3,535,776 joules.