1. MECE 102: Engineering Mechanics Lab A First Year Course in Newtonian Mechanics, Experimentation, and Computer Tools
Created by the Faculty of the Mechanical Engineering Department in the Kate Gleason College of Engineering at RIT

2. Week 6 Lecture Work and Energy We will study:
the motion of a cart moving through a curvilinear path
the tradeoff between Work and Energy that occurs during the motion.
We will be using Video capture to help determine elevations, distances travelled, and velocities of the moving cart.

3. iCLICKER: The week 6 Lab Experiment studies the relationship between Work and Energy transfer. Which one of the following units are typically associated with Energy terms?
Select your Answer:
Joule [J]
Meter [m]
Pascal [Pa]
Hertz [cycles/sec]
Liter [L]

4. iCLICKER: The week 6 Lab Experiment studies the relationship between Work and Energy transfer. Which one of the following units are typically associated with Energy terms?
Select your Answer:
Joule [J]  derived SI unit [J] = [N] [m] derived US Customary unit [ft·lbf]
Meter [m]
Pascal [Pa]
Hertz [cycles/sec]
Liter [L]

5. FORMULATE: State the Known Information
Determine the speed, kinetic energy and potential energy of a vehicle as it traverses the curvilinear path of a track.
Use the difference in total energy between cart positions to estimate the work done by the moving cart upon the track, to overcome the irreversible friction force.

6. Clearly identify values to be determined in analysis:
FORMULATE: Identify Desired Information
Clearly identify values to be determined in analysis:

7. Clearly identify and justify all Assumptions used in analysis:
FORMULATE: Identify Assumptions
Clearly identify and justify all Assumptions used in analysis:

8. CHART: Schematic Diagram
Figure 6.1: Schematic Diagram of a cart rolling down a curved ramp.

9. CHART: Free Body Diagrams𝑘 𝜽 𝑖 𝑛 𝑘 fm 𝑡 𝑖

10. EXECUTE: Recall the Governing Equations
The Conservation of Energy (also known as “The 1st Law of Thermodynamics”) states that “The change in the amount of energy stored within a system during some time interval is equal to the net amount of energy transferred into the system by heat transfer from its surroundings during the time interval, minus the net amount of energy transferred out of the system by work done by the system on its surroundings during the time interval.”
Recall the “HIP-to-WIN” sign convention for energy transfers.

11. Ei references the Total Energy at state i
EXECUTE: Simplify the Governing Equations
Ei references the Total Energy at state i
PEi references the Potential Energy at state i
KEi references the Potential Energy at state i
SEi references the Spring (Elastic) Energy at state i (assumed to be “0” for this experiment)

12. EXECUTE: Simplify the Governing Equations

13. iCLICKER: Which one of the following summarizes the unique position and energy status of the cart as it moves along the track? .
Select your Answer:
State Table
Process Table
Dinner Table
Water Table
None of the above Tables

14. iCLICKER: Which one of the following summarizes the unique position and energy status of the cart as it moves along the track? .
Select your Answer:
State Table
Process Table
Dinner Table
Water Table
None of the above Tables

15. iCLICKER: In Mechanical Engineering “the state of a physical system fully describes the energy status of the system at an instant of time, and is dependent on the path taken to arrive at the state.“
Select your Answer:
True
False

16. iCLICKER: In Mechanical Engineering “the state of a physical system fully describes the energy status of the system at an instant of time, and is dependent on the path taken to arrive at the state.“
Select your Answer:
True
False  The state is INDEPENDENT of the path taken to arrive at the state.

17. CHART: Data Tables
Each row in the STATE TABLE corresponds to one unique position and energy status of the cart as it moves along the track.
Each State, i, corresponds to a unique elevation and the energy condition of the cart when it is at that particular elevation.

18. CHART: Data Tables
Each row in the PROCESS Table describes the exchange of energy, work and heat, as the system moves between states.
A “Process" in Mechanical Engineering fully describes the change between two states of the system over an interval of time, and describes the path taken between states.

19. iCLICKER: Which one of the following is a Scalar value?
Select your Answer:
Force applied to the mass of the cart
Displacement of the cart
Work performed by the cart
Velocity of the cart
None of the above

20. iCLICKER: Which one of the following is a Scalar value?
Select your Answer:
Force applied to the mass of the cart
Displacement of the cart
Work performed by the cart
Velocity of the cart
None of the above

21. WORK as defined in Physics and Mechanical Engineering.
WORK is defined mathematically using the Scalar Product, or Dot Product, of two vectors.

22. EXECUTE: Simplify the Governing Equations
Equation 6.21 is referenced as the Work-Energy Theorem.
Recall that we assumed that there is no Heat Transfer, Q12, occurring between the cart and the surroundings.

23. Given the 2 vectors:. 𝑠 1 =5 𝑖 −2 𝑗 + 7 𝑘 and
Given the 2 vectors: 𝑠 1 =5 𝑖 −2 𝑗 + 7 𝑘 and 𝑠 2 =1 𝑖 +4 𝑗 − 3 𝑘 Compute the Dot Product: 𝑠 1 ∙ 𝑠 2 (also referred to as the “Scalar Product”)

24. Lab Set-up Pictures

25. Homework Prior to LAB tomorrow
Read section 6.2 of the textbook
Watch LAB Videos
Complete the on-line LAB quiz in myCourses
Attempt to solve all assigned chapter problems in your logbook before RECITATION.
Week 6 Problem Set from Section 6.5:        1, 3, 8, 17, 19, 24

26. Questions?