Is The Hand Doing Work? 2B2 p 43
My hand has been exerting a force on the string to support the weight as the object is moving from A to B. Has my hand done any work?
I now keep my hand at the same place and slowly pull in the string (twist over fingers) raising the object from D to C. Has my hand done work in this case?
Which Way Should You Pull? 1C3 p 45
Which Way Should You Pull? Fe on B 35N What is the purpose of the pulley?
Gravity and Simple Pulley 1C1 p 51
When you let go of the two masses, what happens? What did happen? What is your explanation?
What is the Trade-Off for a Smaller Force (Pulleys)? 3B1 p 57
What is the Trade-Off for a Smaller Force How much force does it take to slowly lift the mass? We call this force the weight of the object.
Mount pulley to top support Fasten weight to other pulley String the pulley Hang weight to end of string Add enough weight until the other weight rises Measure din and dout Record weightin and weightout Fout Fin Fout din dout Fin
Workin = Fin x din Workout = Fout x dout Ideal M.A. = din / dout Actual M.A. = Fout / Fin Efficiency = Wout / Win Fout Fin Fout din dout Fin
- Input Work = Input Force x Input Distance Table 1 Input Output Mechanical Situation Force Distance Work Advantage Efficiency (g) (cm) (g-cm) Actual | Ideal A | B C - Input Work = Input Force x Input Distance - Output Work = Output Force x Output Distance How does the work output relate to the work input - Mechanical Advantage Actual = Force Output / Force Input - Mechanical Advantage Ideal = Distance Input / Distance Output What does the mechanical advantage of a lever tell you? - Efficiency = Work Output / Work Input - Can you expect the efficiency of a machine to be over 100%?
What is the Trade-Off for a Smaller Force How does the output distance compare to the input distance? How does the output force, compare to the input force?
What is the Trade-Off for a Smaller Force How does the output distance compare to the input distance? How does the output force, compare to the input force?
MA = 1