Moving Wedge.? A wedge with mass M rests on a frictionless, horizontal tabletop. A block with mass ?m? is placed on the wedge (?Fig. P5.112a?). There is no friction between the block and the wedge. The system is released from rest. (a) Calculate the acceleration of the wedge and the horizontal and vertical components of the acceleration of the block. (b) Do your answers to part (a) reduce to the correct results when M is very large? (c) As seen by a stationary observer, what is the shape of the trajectory of the block?
LECTURE NOTES FROM 3/14/16 Arms Control Critiques/Problems: • Inspection o Logistically difficult (not willing to let inspectors in) o Requires proof of no activity o Hard to eliminate distrust • Enforcement o How to punish violators § Initiate the violation/consequence • *Deals do no eliminate conflict, but only manage it (prevent it from escalating) o reduces risks/costs • Only deals with obsolete weapons • Channels competition into unregulated areas o Encourages weapon innovation • Is there a long-term benefit to arms control agreements o For certain weapons, it is good to limit them! However… -‐Doesn’t eliminate overall conflict between states NO NOTES FROM LECTURE 3/16/16 _______________________________________________________ Recitation 3/16/16 Arms Control: • Limit costs • Limit risks of conflict • Limit harms of conflict (humanitarianism) • Qualitative vs. Quantitative o Qualitative § NNPT, CWC,BWC,ABM, INF Landmines, cluster munitions o Quantitative: § Washington naval treaties, salt, start, etc. Arms Control Problems: • Verification/enforcement • Risk of violations • Dual-use technologies • Changing power Collective Defense: • A group of countries agreeing to defend each other from attacks that come from outside the group o Similar to alliances, but more organized § NATO is a primary example Collective Security: • An agreement among countries to create peace and security o All countries renounce use of force in disputes o Agree that everyone will attack any member that violates the agreement o Expects potential threats to be within the organization § League of Nations ú Article 16: Immediate sanctions against any member who commits an act of war against one of the members, all members will contribute armed forces to enforce the treaty, all members will allow passage of forces through their territory to enforce the treaty. • Examples of violations: o Japan invasion of Manchuria o Italy invades Ethiopia o Chaco War § United Nations ú Chapter 1, Article 2 • All members shall settle their international disputes by peaceful means • Security council decides whether there is a violation and what to do o Examples of violations: § Korean War, Gulf War
