Question

Car drag racing takes place over a distance of a mile (402 m) from a standing start. If a car (mass 1600 kg) could be propelled forward with a pulling force equal to that of gravity, what would be the change in kinetic energy and the terminal speed of the car (in mph) at the end of the race be? (For comparison, a modern, high-performance sports car may reach a terminal speed of just over 100 mph = 44.7 m/s.)

Answer 1

Answer:

v = 88.76 m / s ,  K = 6.30 10⁶ J

Explanation:

For this exercise the force that is applied is that necessary for the acceleration of the car to be the acceleration of gravity, they do not indicate that there is friction, we look for the final speed

       v² = v₀² + 2 a x

Since the car starts from rest, the initial speed is zero, vo = 0

       v = √ 2 a x

       v = √ (2 9.8 402)

       v = 88.76 m / s

Let's look for kinetic energy

       K = ½ m v²

       K = ½ 160kg 88.76²

       K = 6.30 10⁶ J