Kinetic energy and velocity of electron after compton scatte

[DeathByKugelBlitz]

Homework Statement

A photon with an initial wavelength of 0.1120 nm collides with a free electron that is initially at rest. After the collision the wavelength is 0.1140 nm .

a) What is the kinetic energy of the electron after the collision?

b) What is its speed?

c) If the electron is suddenly stopped (for example, in a solid target), all of its kinetic energy is used to create a photon. What is the wavelength of this photon?

Homework Equations

E = hf = pc
p = E/c = hf/c = h/λ
λ' - λ = h/mc(1 - cos∅)

The Attempt at a Solution

E = hc/λ - hc/λ' = hc(1/λ - λ')

= 9.945 x 10⁶ which is marked as incorrect

This would make my answers to parts b) and c) incorrect too

 

[DeathByKugelBlitz]

I'm so dumb. The correct way to re-arrange the equation is E = hc(1/λ - 1/λ')

I used this and got all three parts correct