A 1447 kg car accelerates from a complete stop at a traffic light to a speed of 28.5 m/s in 73 seconds (the car is on a perfectly flat surface). The ground exerts a horizontal force on the tires preventing them from slipping as the car accelerates. 1. What is the average of this force for the entire experiment?
2. If the tire does not slip at its point of contact (where the force is acting), how far does the force displace the tire? Thus, how much work is done on the real car system by this force?
3. Consider, rather, an equivalent force displacing a point-particle in space. How much work does the force do?
4. Since the kinetic energy of the car is increasing, conservation of energy tell us some other energy in our system must be decreasing. If the car's tires do not significantly increase in temperature, what kind of energy is decreasing?
i. gravitational potential energy
i. thermal energy
iii. rotational kinetic energy
iv. translational kinetic energy
v. chemical energy
5. Considering your answer above, what is the total change in this energy throughout the entire experiment? J