1. ENGR 215 ~ Dynamics Sections 13.1 – 13.3

2. Newton’s Three Laws of Motion First Law –a particle originally at rest, or moving in a straight line with constant velocity, will remain in this state provided the particle is not subjected to an unbalanced force. Second Law –a particle acted on by an unbalanced force experiences an acceleration that has the same direction as the force and a magnitude proportional to the force. F = ma. Third Law –mutual forces of action and reaction between two particles are equal, opposite and collinear.

3. Inertial Reference Frames Does not rotate. Either fixed or moving at constant velocity. Acceleration is zero.

4. Rockets??? What do we use as an inertial reference frame for rocket science?

5. Newton’s Second Law

6. Lecture Example 1: Determine the tension in the cable and the acceleration of the 8 kg block after it is released from rest. Determine the position of the block 1s after it is released from rest.

7. Lecture Example 2: Determine the speed of the 6 kg block after 2 seconds if the block start from rest.