Levers and Pulleys

Lever and Pulley Jeopardy Definitions Levers Pulleys Simple Machines Challenge??? 10 pt 20 pt 30 pt 40 pt 50 pt Bonus

What is a simple machine? Any of the six basic devices that provide mechanical advantage Now with your group list the 6 basic devices.

What is the tool we used to measure force/effort and what unit does it measure in? The spring scale Newton

What is mechanical advantage? Reduces the force needed to lift a load and is the result of using a simple machine.

What is a pulley? A wheel with a grooved rim in which a rope can run to change the direction of the force that lifts the load.

What is directional advantage? Is a change in direction that results from passing a rope through a pulley. The direction we would pull would be down. With gravity.

A pair of scissors is what class of lever? Diagram on your white board

A hammer is what class of lever? A class-1 lever now diagram it on your white board

A pair of tweezers is what class of lever? Now diagram the tweezers on your white board

A fishing rod is what class of lever A class-3 lever Diagram this lever on your white board

Which lever system would you use to lift the load? B C A seesaw B

What is a single-fixed pulley? Has a wheel that is attached to something above the load

A Directional B Mechanical C Mechanical/Directional D- Directional What type (s) of advantage does each system give?

Which pulley systems will not work? A B C

Which pulley systems will work properly? Z

If you have a load that weighs 240N and you use a pulley with 4 supporting ropes, how much effort will you need? 60N.

A cars tires when connected to the car are an example of what type of simple machine Wheel and axle.

In order to get the water to drain out of your bathtub you need this simple machine. What is an inclined plane

In the kitchen you use knives to chop and cut food In the kitchen you use knives to chop and cut food. A knife is this type of simple machine What is a wedge?

We use light bulbs all over our houses We use light bulbs all over our houses. A light bulb is this type of simple machine. A screw.

Most of us use stairs everyday Most of us use stairs everyday. A staircase it this type of simple machine. Inclined plane

If all the boxes weighed the same, which picture most accurately represents what the seesaw would look like when stopped? B C A A

What would the effort be at 13 cm? ~2 N

Shaelyn is investigating the 4 different pulley systems and how they provide advantage. She uses 12 inches or rope, a 2.4N load, a spring scale, and 1-2 pulleys. Write a possible testable question she could have?. Answers may vary.

Write a hypothesis for this testable question Write a hypothesis for this testable question. “How the location of the fulcrum effect the amount of effort needed to lift the load?” If…….then I think….will ……

On the Measuring the Distance investigation this was our LOL. The benefits gained (making work easier) by using simple machines are always balanced by cost When the benefit out weighs the cost, the machine is a useful tool.

Bonus Question http://www.fossweb.com/modules3- 6/LeversandPulleys/index.html