Conservation of Energy Question

[smr101]

Having problems with part (c) here, question is attached below in full.

Homework Statement

Using the equation 1/2 * Load * Displacement = Sum of (P^2 * L/2AE)

From the past questions I have the following info, these are also included in the solutions so are accurate:

A = 1x10^3 m^2
FAB = 90kN
FBC = 120kN
Length of AB = 1.5 m
Length of BC = 2 m

Homework Equations

The Attempt at a Solution

My attempt at the solution:

1/2 * 150 x 10^3 * Displacement = 1/(2 * 1x10^-3 * 205x10^9) * ((90x10^3^2 * 1.5)+ (120x10^3^2 * 2))

Displacement = ((90x10^3^2 * 1.5)+ (120x10^3^2 * 2)) / 1x10^-3 * 205x10^9 * 150x10^3

= 1.33 mm

The correct answer, per the solutions, is 2.08 mm.

Any idea where I've gone wrong?

Thanks.

 

[smr101]

Any ideas?