Web sources:
"Trebuchet Physics." Real World Physics Problems. N.p., n.d. Web. 23 Nov. 2016.
"Trebuchet Physics." Real World Physics Problems. N.p., n.d. Web. 23 Nov. 2016.
<http://www.real-world-physics-problems.com/trebuchet-physics.html>
"The Lever Introduction." Archimedes' Lever. N.p., n.d. Web. 23 Nov. 2016.
<https://www.math.nyu.edu/~crorres/Archimedes/Lever/LeverIntro.html>
"Friction and Friction Coefficients." The Engineering
Toolbox. N.p., n.d. Web. 23 Nov.
2016.
<http://www.engineeringtoolbox.com/friction-coefficients-d_778.html>
Teaching Simple Machines." Resource Information for Teaching Simple Machines. N.p., n.d. Web. 23 Nov. 2016.
<http://www2.phy.ilstu.edu/pte/489.01content/simple_machines/simple_machines.html>
Journal Source:
2016.
<http://www.engineeringtoolbox.com/friction-coefficients-d_778.html>
Teaching Simple Machines." Resource Information for Teaching Simple Machines. N.p., n.d. Web. 23 Nov. 2016.
<http://www2.phy.ilstu.edu/pte/489.01content/simple_machines/simple_machines.html>
Journal Source:
O'Connor, Leo. "Building A Better Trebuchet." Mechanical Engineering 116.(1994): 66-69. Applied Science & Technology Full Text (H.W. Wilson). Web. 23 Nov. 2016.
Text Book:
Knight, Randall. Physics for Scientists & Engineers: A Strategic Approach with Modern Physics, 3rd Ed. Pearson, 2013.