a) Fspring = - k x
b) W = - ∫xi xf k x dx
c) W = - 0.5 k ( xf^2 - xi^2 )
d) W = -9.792
The complete question is: A mass is sliding on a frictionless surface with a speed v. It runs into a linear spring with a spring constant of k, which compresses from position xi to position xf.
a) Write a general expression for the force that the spring exerts on the mass, in term of k and x. Choose the initial position of the front of the spring to be xi=0.
b)Select the equation that correctly describes the work done by the spring to stop the mass.
c) Evaluate the relationship in part (b) to arrive at an expression for the work done in terms of known variables.
d) Solve for the numerical value of the work done in Joules given that xi = 0, xf = 48 cm, and k = 85 N/m.