posted by Ashley .
I really need help on D part of the following problem:
A clever engineer designs a "sprong" that obeys the force law F subscript e = -q(x - x subscript e)^3, where x subscript e is the equilibrium position of the end of the sprong and q is the sprong constant. For simplicity, x subscript e = 0m . Then F subscript x = -qx^3.
What are the units of q? N/m^3 (correct)
Find an expression for the potential energy of a stretched or compressed sprong. U(x) = 1/4qx^4 (correct)
A sprong-loaded toy gun shoots a 24 g plastic ball. What is the launch speed if the sprong constant is 4.3 × 10^4 N/m^3, with the units you found in part A, and the sprong is compressed 11 cm? Assume the barrel is frictionless.