Posted by asia on .
A 1100 kg car rolling on a horizontal surface has speed v = 70 km/h when it strikes a horizontal coiled spring and is brought to rest in a distance of 2.2 m. What is the spring stiffness constant of the spring?

physics 
drwls,
The car comes to rest (temporarily)at compression distance X, at which point the initial kiteci energy (1/2) M V^2 is converted to spring potential energt, (1/2)kX^2.
Therefore
kX^2 = mV^2
k = m (V/X)^2
Make sure you convert V to meters per second before using the formula. k will be in Newtons/meter