1. What did you learn about electrical work in the last class?? On page 65 fill in the blanks using complete sentences/thoughts. Now I know That ________________ I still want to know ________________________. I am glad that I learned that__________________ because__________________________________. Bell ringer: Now I Know……..

2. Lab 2.3A Page 68

3.  Objectives: Determine the work input to an electric motor Determine the work output of an electric motor Determine the efficiency of the motor (Compare the work output of an electrical motor to the work input to the motor)  Lab Proficiencies: Set up a system to measure work input to an electric motor as it lifts a load Set up and perform an experiment to measure the work done by an electric motor while lifting a load Measure the voltage across and current through a motor Devise a method to measure constant speed when lifting a hanger and mass 68

4.  Materials: DC Motor Power Supply Meter Stick Single Pulley with Bracket Small Weight Hanger Universal Lead Set Long Crossbar Rod Connectors, 3 5/64 “ Allen Wrench Stop Watch Spool Pulley Nylon Cord Hook Small Slotted Weight Set S-Hook Mechanical Breadboard Support Rod with Base, 2

5. 1. Bring your notebook, pencil, and calculator (if you brought it). 2. Assign roles and write your group members and their roles on the bottom first page of your lab data sheet. 3. Send your Materials Manager to collect safety glasses (sanitized) and a calculator for your group. 4. Have your Head Physicist read the Discussion to everyone. Head Physicist makes sure everyone understands the concepts before proceeding with the lab. 5. Wear your safety glasses AT ALL TIMES and begin. 6. Lab Instructions will be on your lab table. 7. Submit 2.3A Data Sheet today.

6.  When I walk by I want to hear the HEAD PHYSICISTS reading the discussion and procedures out loud to the rest of the group.  SAFETY WARNINGS! There are moving parts in this lab!! All hair should be tied back, loose clothing properly taken care of and hanging objects tucked or removed. Safety goggles should be worn at all times because flying objects are a possibility. Turn the current knob SLOWLY!!!!!!!!!!!!!!!!!!!!!! Materials Manager will spot the lifted load AT ALL TIMES. I don’t want to hear any weights hit the floor or walls!! ABSOLUTELY NO HORSEPLAY WILL BE TOLERATED!! We are dealing with electricity, a motor and weights which all can equal a disaster if not paying attention!!! BE ALERT OR YOU WILL GET HURT!

7. EXIT SLIPHOMEWORK:  Turn in your lab 2.3A Data Sheet before you leave.  You must finish ALL the data and questions before you leave!!!  Finish your Lab write up in your notebook  It will be checked/stamped next time.  It goes on page 67.

8.  Procedure At least 6 numbered steps At least 6 numbered steps Should be easy to follow Should be easy to follow May use diagrams May use diagrams  Conclusion: Did you meet your objective? Why or why not? Did you meet your objective? Why or why not? What possible sources of error could have affected your data? What possible sources of error could have affected your data? What did you learn from this lab? What did you learn from this lab? How was your group able to rely on your in your assigned role? How was your group able to rely on your in your assigned role? 67