The brakes did 4,860,000 joules of work to stop Ricky Bobby's racing car with a mass of 2700 kg and an initial velocity of 60 m/s.
The question is asking us to calculate the work done by the brakes to bring Ricky Bobby's racing car to a halt. According to the work-energy principle, the work done by the brakes is equal to the change in kinetic energy of the car. Since work is the force exerted over a distance and kinetic energy is ½ mass times velocity squared, we can express the work done by the brakes (W) as:
W = ½ mv²
This formula assumes that Ricky Bobby's car is coming to a stop without any external work other than the brakes being applied. Given that the car's mass (m) is 2700 kg and its initial velocity (v) is 60 m/s, we can use the formula to calculate the work:
W = ½ x 2700 kg x (60 m/s)²
W = ½ x 2700 kg x 3600 (m²/s²)
W = 0.5 x 2700 kg x 3600 m²/s²
W = 4,860,000 J (joules)
Therefore, the brakes did 4,860,000 joules of work to stop Ricky Bobby's racing car.