Explicit Central Difference Method 2 Node Bar (Matlab Coding)

Hi,

I am having trouble getting started on my assignment. I need to use the explicit central difference method to calculate displacement with respect to time at the second node of a standard 2 node bar.

I have boundary condition d1(t)=0 (Displacement at node 1) I also have initial conditions: d2(t=0)=0.1 (initial displacement of node 2) and d2t/dt^2(t=0)=0 (initial velocity of node 2)

I also have given information: E=1000 (Young's Modulus), p=0.0001 (density), A=1 (area), and L=10 (Length of bar)

I need to plot displacement of node 2 (d2(t)) vs time (t. I need to alter time increments and time steps as shown below: Case 1: Time increments=0.001 Time Steps=50 Case 2: Time increments=0.0005 Time Steps=100 Case 3: Time increments=0.00025 Time Steps=200

Any help would be greatly appreciated. I could really use some direction of how to start out at least. Thank you very much!