You devise a wind-up car powered by a spring for trips to the grocery store. The car has an inertia of 520 kg and is 4.1 m long. It should be able to accelerate from rest to 20 m/s at least 50 times b

You devise a wind-up car powered by a spring for trips to the grocery store. The car has an inertia of 520 kg and is 4.1 m long. It should be able to accelerate from rest to 20 m/s at least 50 times before the spring needs winding. The spring runs the length of the car, and a full winding compresses it to half this length.