Levers
What is the fixed point on a lever called?
Fulcrum
What is a gear train?
A group of two or more gears working together.
What is the mechanical advantage of a single fixed pulley?
1
If you apply a force but don’t move the object, how much work is done?
Zero
What is the formula for efficiency?
Efficiency = (Work Output / Work Input) × 100
In a Class 2 lever, where is the load located?
In the center
If the driver gear is larger than the follower gear, what advantage do you get?
Speed advantage
How does a movable pulley differ from a fixed pulley?
A movable pulley moves with the load, while a fixed pulley stays in place.
What is the mechanical advantage if a 5 N effort moves a 10 N load?
2
If a machine has 400 J of output work and 500 J of input work, what is its efficiency?
80%
What is the formula for calculating work?
Work = Force × Distance
What are gears linked by a chain called?
Sprockets
What happens to the mechanical advantage when you add more movable pulleys?
It increases (doubles with each additional movable pulley).
What does a mechanical advantage less than 1 indicate?
A speed or distance advantage (but greater effort force).
Name one way to boost a machine’s efficiency.
Adding lubricants, proper maintenance, reducing friction, etc.
Name an example of a Class 3 lever.
Hockey stick, baseball bat, or tweezers
How does a wheel and axle function like a lever?
The axle acts like the fulcrum of a rotating lever.
What is another name for a compound pulley system?
Block and tackle
Why is the output work of a machine always less than the input work?
Due to energy loss (e.g., friction).
Why is friction sometimes useful in machines?
It prevents slipping (e.g., car tires on roads).
If the load is closer to the fulcrum, what happens to the effort needed to move it?
It becomes easier (less effort is required).
What is the speed ratio formula for gears?
Speed Ratio = Number of driver gear teeth / Number of follower gear teeth
If a pulley system has an M.A. of 4, how much effort is needed to lift a 100 N load?
25 N
What is the unit for mechanical advantage?
It has no unit (it’s a ratio).
What is the main cause of energy loss in machines?
Friction