Mechanical Advantage
Are there units to represent MA? Why or why not?
No. Mechanical advantage is a ratio of input to output work.
What are the 6 simple machines?
The six simple machines are lever, pulley, wheel and axle, inclined plane, wedge, and screw.
What unit is work measured in?
Joules
Name a hydraulic and a pneumatic system in the human body.
hydraulic: circulatory system
pneumatic: respiratory system
In a gear train with two gears, how do you determine which has a higher speed?
The gear with fewer teeth (smaller size) has a higher speed.
Solve for MA: Input force is 8N, Output force is 100N
12.5
A machine made up of multiple simple machines working together is called what?
Complex machine.
Define work and give a counterexample where force is applied but no work is done.
Work is the transfer of energy through force applied over a distance.
A counterexample: Pushing against a wall applies force but does no work because the wall doesn’t move.
Calculate pressure if the area is 0.5m² and the force applied is 250N.
500 Pa
What is the purpose of a fixed pulley? Can you give an example?
To change the direction of the force.
Ex: Raising a flag on a flag pole.
List 2 ways you could alter a class 1 lever to decrease the effort force that needs to be applied
1. Move the fulcrum closer to the load or the load closer to the fulcrum
2. Increase the length of the effort arm
How do you differentiate a class 1, 2, and 3 lever?
First-class levers have the fulcrum between effort and load, second-class levers have the load between the effort and fulcrum, and third-class levers have the effort between the load and fulcrum.
Solve: An 80N force moves an object 12m uphill. What is the work done?
960J
What is Pascal's Law?
Pressure exerted on a contained fluid is transmitted undiminished in all directions in the fluid
What is the speed ratio of a bicycle chain with a driver gear of 50 teeth and a follower gear of 34 teeeth?
1.47
If a machine has an MA of 3, how much input force is needed to lift a 90N load?
30N
What class lever is a hockey stick?
class 3
As Brandon spikes a volleyball with 1.5 meters using 70 000J, how much force does he hit with?
46666.67N
Compare hydraulic and pneumatic systems in terms of practical applications.
Hydraulic systems rely on liquid, while pneumatic systems use compressed air. Hydraulic systems are more precise and powerful; pneumatic systems are more cost-effective and faster.
What is a block and tackle?
A block and tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads.
Describe a real-life scenario where MA is critical and explain its impact.
A real-life scenario like using a car jack demonstrates how MA amplifies force, allowing users to lift heavy loads with minimal effort.
Explain how a wheel and axle reduces effort.
A wheel and axle reduce effort by spreading force over a larger distance through rotation.
Analyze the relationship between energy loss (due to friction) and work efficiency.
Energy loss, often due to friction, directly impacts efficiency—machines with high energy loss are less efficient in performing work.
Explain how Pascal’s Law is applied in hydraulic brakes to ensure safety.
Hydraulic brakes use Pascal’s Law to amplify force, ensuring safety by evenly distributing pressure to the brake pads.
Draw a pulley system with a MA of 3
Answers may vary.