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Copy of Work: Tools & Simple Machines
Transcript of Copy of Work: Tools & Simple Machines
Work & Force
Is a handicapped ramp a machine?
Give me an example of when you have ever used any of these simple machines in real-life.
A basic mechanical device for applying force.
A device that makes doing work "easier" by increasing force or changing its direction.
Why do we want machines to be efficient?
What does that mean?
A measure of how much of the work put into the machine is changed into useful output work by the machine.
Tools & Simple Machines Lab
Today you will complete a lab using ONE simple machine.
The force you apply to the machine
The force that comes out of the machine.
How did these compare in the machine you used in the lab?
Ratio of input force to output force.
MA = Fout
What was the Mechanical Advantage (MA) for the inclined plane?
Ratio of work in to work out.
Efficiency = Output Work
How efficient was the ramp?
Two or more simple machines put together.
Rube Goldberg Machine
Just for fun...
Most machines you think of are COMPOUND machines!
A deliberately over-engineered or overdone machine that performs a very simple task in a very complex fashion.
Let's Practice some Problems!!!
Go get one of these:
I put 12.34N of Force into a wrench with my hand. The wrench then turned a bolt with a force of 59.21N. Calculate my Mechanical Advantage.
A pulley raised a box with 1302.7N of force after I pulled the rope with 205.3N of force. What is the Mechanical Advantage?
I do 28.45J of work turning a screw. The screw applies 24.34J of work to the board. How efficient is the screw?
Write down as many simple machines as you can find in this video!!!!
Spring Scale: Use to measure the FORCE in NEWTONS!
Ruler: Use to measure the DISTANCE in either CM or M!
What is mechanical advantage and how can I calculate it?
Please take out a blank piece of paper and write "simple machines lab" at the top.
1. What type of simple machine is it?
2. Prediction: Do you think it will require more force to lift the box straight up or drag it up the ramp?
3. Draw this table:
With or without machine
4. How do you think the ramp reduces the force necessary to raise the box??? Take a guess.
MA Practice Problem
To pull a weed out of a garden, you can apply a force of 50 N to the shovel. The shovel applies a force of 600 N to the weed. What is the mechanical advantage of the shovel?
Wheel with a grooved rim around which a cord passes. Used to raise heavy weights.
More wheels = Less force to pull!!!
Which pulley will require the LEAST force?
Which pulley with require the MOST distance?
Which pulley will you need to apply the LEAST AMOUNT OF FORCE to?