You are asked to design spring bumpers for the walls of a parking garage. A freely rolling 1200-kg car moving at 0.65 m/s is to compress the spring no more than 0.090 m before stopping. What should be the force constant of the spring? Assume that the spring has negligible mass.

Solution 79P Step 1 of 4: In the given problem, the work done by the car on the ground during parking will be equal to the maximum work that string can withstand which is placed at parking. Using this logic we can calculate the force constant of the string. That is , when the car of mass m=1200 kg moving with speed v=0.65 m/s comes to rest on the parking, the change in kinetic energy gives the work done by the car on ground. This work done will be equal to the maximum work the spring can withstand to undergo a maximum compression of 0.09 m. Step 2 of 4: To calculate work done by parking car, Given data, Mass of car, m=1200 kg Initial speed, i = 0.65 m/s Final speed, v f 0 To find Work done by car on ground, W=