UNIT 03 - Work, Power & Energy
1. Work and the Work-Energy Theorem
2. Forces & Potential Energy
3. Conservation of Energy
4. Power - Students should understand the definition of power, so they can:
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UNIT 03 - Work, Power & Energy
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1. Work and the Work-Energy Theorem |
| A) Students should understand the definition of work, including when it is positive, negative, or zero, so they can: |
| (1) (1) Calculate the work done by a specified constant force on an object that undergoes a specified displacement. (3.1) |
| (2) Relate the work done by a force to the area under a graph of force as a function of position, and calculate this work in the case where the force is a linear function of position. (C 3.2) |
| (3) Use integration to calculate the work performed by a force F(x) on an object that undergoes a specified displacement in one dimension (C 3.3) |
| (4) Use the scalar product operation to calculate the work performed by a specified constant force F on an object that undergoes a displacement in a plane (C 3.4) |
2. Forces & Potential Energy |
| A) Students should understand the concept of a conservative force, so they can: |
| (1) State alternative definitions of “conservative force” and explain why these definitions are equivalent. (C 3.5) |
| (2) Describe examples of conservative forces and non-conservative forces (C 3.6) |
| C) Students should understand the concept of potential energy, so they can: |
| (1) State the general relation between force and potential energy, and explain why potential energy can be associated only with conservative forces (C 3.7) |
| (2) Calculate a potential energy function associated with a specified one-dimensional force F(x) (C 3.8) |
| (3) Calculate the magnitude and direction of a one-dimensional force when given the potential energy function U(x) for the force (C 3.9) |
| (4) Write an expression for the force exerted by an ideal spring and for the potential energy of a stretched or compressed spring (C 3.10) |
| (5) Calculate the potential energy of one or more objects in a uniform gravitational field (C 3.11) |
3. Conservation of Energy |
| A) Students should understand the concepts of mechanical energy and of total energy, so they can: |
| (1) State and apply the relation between the work performed on an object by non-conservative forces and the change in an object’s mechanical energy (C 3.12). |
| (2) Describe and identify situations in which mechanical energy is converted to other forms of energy (C 3.13) |
| (3) Analyze situations in which an object’s mechanical energy is changed by friction or by a specified externally applied force (C 3.14) |
| B) Students should understand conservation of energy, so they can: |
| (1) Identify situations in which mechanical energy is or is not conserved (C 3.15) |
| (2) Apply conservation of energy in analyzing the motion of systems of connected objects, such as an Atwood’s machine (C 3.16) |
| (3) Apply conservation of energy in analyzing the motion of objects that move under the influence of springs (C 3.17) |
| (4) Apply conservation of energy in analyzing the motion of objects that move under the influence of other non-constant one-dimensional forces (C 3.18) |
| C) Students should be able to recognize and solve problems that call for application both of conservation of energy and Newton’s Laws (C 3.19) |
4. Power - Students should understand the definition of power, so they can: |
| (A) Calculate the power required to maintain the motion of an object with constant acceleration (e.g., to move an object along a level surface, to raise an object at a constant rate, or to overcome friction for an object that is moving at a constant speed (C 3.20) |
| (B) Calculate the work performed by a force that supplies constant power, or the average power supplied by a force that performs a specified amount of work (C 3.21) |