f)
Conservation of energy tells us:
(current energy of system) = (initial energy of system)
(current energy of car) + (current energy of spring) = (initial energy of car) +(initial energy of spring)
(current kinetic energy of car) + (current potential energy of car) + (current potential energy of spring) + (current kinetic energy of spring) = (initial kinetic energy of car) + (initial potential energy of car) +(initial kinetic energy of spring) +(initial potential energy of spring)
the strike through parts are all 0, therefore:
(current kinetic energy of car) + (current potential energy of spring) = (initial kinetic energy of car)
(current kinetic energy of car) = (1/2)*2200*v^2
(current potential energy of spring) = (1/2)*k*x^2 = (1/2)*k*x^2 = (1/2)*850*1.5^2
(initial kinetic energy of car) = (1/2)*m*v^2 = (1/2)*2200*1.7^2
plugging those in:
(1/2)*2200*v^2 + (1/2)*850*1.5^2 = (1/2)*2200*1.7^2
v = 1.4 m/s
This post was edited by Azrad on Nov 13 2013 07:04am