What makes a roller/wheel and axle useful? (how does it work)
Reduces friction
Name this pulley. fixed, movable or compound
Compound
Which is the Driver gear?
The one attached to the pedal
What class of lever is this
First
What is a controlled variable?
A variable that we keep constant, or the same so it doesn't interfere with the variable that we are actually testing.
Name one example of when a Roller is a better choice than a wheel and axle. Why?
Answers will vary
Name this Pulley. Fixed, Moveable, Compound
Fixed
Name one disadvantage to a wheel to wheel gear system such as the one show here
They go in opposite directions
What class of lever is this?
3rd Class
What is a manipulated variable?
The variable that we are testing. The single thing that we will change in the experiment
Why did the invention of the wheel and axle make such a huge difference to transportation?
Because it allowed us to attach the object we are moving to the wheels.
Name this pulley. Fixed, Movable, Compound
Moveable
How can I build a wheel to wheel gear system where the driver and the driven gear are going the same direction?
What class of lever is this?
2nd class lever
What is a responding variable?
The variable that will give us the result. The variable that changes because we changed something else.
What might be a disadvantage of a wheel and axle?
answers will very
When using a specific compound pulley I have a mechanical advantage of 4. Meaning my load only ways 1/4 of what it would without the pulley. What is the cost?
I will have to pull the string 4x further.
If I I have very strong legs and wanted to go as fast as possible on my bike, Should I make my Driver gear bigger or smaller? Why?
Bigger. Because for each lap around the pedal the wheel will turn more times. It will feel heavier but I will go faster.
Why is this such an effective First class lever?
Because the fulcrum is so close to the load
If I want to test if students are more excited about Diwali or Christmas and I sent a survey about their excitement levels before each holiday to test. What is my responding variable?
Student excitement levels
I want to test how much of a mechanical advantage my rollers are giving me. I use a 5lb brick and drag it across the carpet with a spring scale. I do the same while using the rollers. Name one controlled variable
The weight of the load. other answers may be acceptable.
I want to know if a movable pulley has the same mechanical advantage as a fixed pulley. I test this by lifting a 1kg weight with both types of pulleys and measure the amount of effort needed. What is my responding variable?
The amount of effort needed to lift the 1kg load.
btw. The movable pulley has a mechanical advantage and the fixed does not
I want to test how the mechanical advantage of a gear system changes when the driver gear changes sizes. I Test this by using a small medium and large driver gear. What is my manipulated variable?
The size of the driver gear
How would I increase the mechanical advantage of a 2nd class lever?
By moving the load closer to the fulcrum
If I want to test if students are more excited about Diwali or Christmas and I sent a survey about their excitement levels before each holiday to test. What is my Manipulated variable?
The holiday