Simple Machines Work SYSTEMS IN ACTION Simple Machines

Simple Machines & Work SYSTEMS IN ACTION

Simple Machines � Simple Machine – A device, composed of only one or two parts, that requires a single force to work. � Mechanisms of most physical systems are made of one or more simple machines that work alone or together to make physical tasks like nailing, cutting, carrying easier. � There are six simple machines: Inclined Plane Wedge Screw Lever Wheel & Axle Pulley

Simple Machines � Which simple machine is each picture representing? Inclined Plane Wedge Screw Lever Wheel & Axle Pulley

Work: An Overview � Work – The result when a force moves an object a certain distance. � The amount of work needed for a specific task depends on 2 things: 1. The force applied 2. The distance over which the force is applied � You can calculate the amount of work you did by multiplying the force (in Newtons) by the distance (in metres). � Work = Force x Distance

The Inclined Plane � Inclined Plane – A ramp or a slope that reduces the force you need to exert to lift something. � For the following representation: � Draw the chart displayed in your notes � Sample the different distances and record the data as a class � With the data, calculate the amount of work (Nm or J) � Answer the following questions: 1. Describe the relationship you see with the inclined plane. 2. What do you notice with your “Work” calculations in your successful attempts? What does this mean? � Inclined Plane Representation

The Inclined Plane 1. Describe the relationship you see with the inclined plane. � As you increase the distance of the plane, you decrease the effort force needed (and vice versa). 2. What do you notice with your “Work” calculations? What does this mean? � All answers equal around the same amount of work. Therefore, it is possible to produce the same amount of work with less effort force applied. However, you need to increase the distance of applying the force. This also allows people to push heavier objects with less force. You just need to have a longer inclined plane.

Inclined Plane Lab � Lab: Inclined Plane Lab Setup

Wedges Wedge A modified inclined plane that can be moved back and forth with ease � Wedges are used to change the direction of force. The force is applied down onto the wedge, and the force is redirected to the sides � Wedges & Wedgies � � Examples: � Work relationship for a wedge? � Sample the different sized wedges (Wedge Representation), and notice the amount of effort force needed. What is the relationship? � The longer the wedge, the less force is needed to be applied to it.

Screws Screw � Screw - An inclined plane that has been cut into a central core. � An Archimedes screw (augers), an enlarged modified version of the screw, is used for lifting water and even in Zambonies to clean an ice surface.

Homework 1. With inclined planes, what is the relationship between effort force and distance applying the force? 2. With wedges, what is the relationship between effort force and length of the wedge (distance)? 3. Using the relationship from question 1, explain how you can push heavy objects with less effort.