Mechanical Systems: Going Further
Mechanical advantage, work and efficiency, calculated on real machines.
8 questions, free, marked as you go with a worked explanation on every one.
What this covers
- mechanical systems
The questions
- A lever lets a 50 N effort lift a 350 N load. What is its mechanical advantage?
- A wheelbarrow has the load between the wheel and the handles. Which class of lever is it, and where is the fulcrum?
- A worker pushes a crate 4 m along the floor with a steady force of 75 N in the direction of motion. How much work is done, in joules?
- A machine has 600 J of work put in and does 480 J of useful work. What is its efficiency, as a percentage?
- Why is no real machine 100 percent efficient? Select all that apply.
- A machine has a mechanical advantage of 5. What does that tell you about the distance the effort must move?
- Two gears mesh. The driver has 10 teeth, the driven has 40. What happens to speed and to turning force?
- A student oils a squeaking bicycle chain and the bicycle becomes easier to pedal. Which explanation is best?