Mechanical Systems: More Practice
Gear and pulley mechanical advantage, and how efficiently a machine converts input work into useful output.
8 questions, free, marked as you go with a worked explanation on every one.
What this covers
- mechanical systems
- energy efficiency
The questions
- A driver gear has 10 teeth and turns a driven gear with 40 teeth. What is the mechanical advantage of this gear train?
- In the same gear train, the 10-tooth driver gear turns at 80 RPM. What speed does the 40-tooth driven gear turn at, in RPM?
- In a class 1 lever, where is the fulcrum located?
- A lever is used to lift a load, with an input force of 20 N producing an output force of 100 N. What is its mechanical advantage?
- A pulley system uses 4 supporting ropes to lift a load. Ignoring friction, what is its mechanical advantage?
- Use the table below, showing three machines and how much of their input work becomes useful output work. Which machine is the most efficient?
- A machine converts 100 J of input work into 60 J of useful output work. What is its efficiency, as a percent?
- Which of these changes reduces the energy a mechanical system loses to friction?