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Levers. Today’s Lesson. More information on levers How to write an experiment Introduction to Design Task Start Design Task. Levers. A lever has three different areas: Fulcrum: A fulcrum is the point where a lever rests or is supported.
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Today’s Lesson • More information on levers • How to write an experiment • Introduction to Design Task • Start Design Task
Levers • A lever has three different areas: • Fulcrum: A fulcrum is the point where a lever rests or is supported. • Load: The area where weight is carried or moved. The opposition to applied force. • Effort: The force applied to an object or machine to cause motion.
1st Class Levers • First class levers are force multipliers. • Having the load close to the fulcrum will have a high mechanical advantage. • Having the load far from the fulcrum will have a low mechanical advantage. • Examples include scissors, can opener, elbow etc.
Second Class Lever • Second class levers go in this order. • Fulcrum • Then Load • Then Effort • Examples include nut crackers, wheel barrows and your jaw. • They are force multipliers which make our job easier. http://www.usask.ca/consumer_services/bookstore/pro_reference/anatomical_models/index.php
Third Class Levers • Third class levers are speed multipliers – which means a lot of force can occur in a small area. • Third class levers go in this order: • Fulcrum • Then Effort • Then Load
Questions Write down the following questions in your notes book and answer them in sentences. • What are the main differences between the three types of levers? Explain. • What are the main uses for the 3 different types of levers? • Give 2 examples of each lever which were not mentioned in this PPT.
Research Question & Hypothesis • A Research Question is a question that you are trying to answer through doing the experiment • A hypothesis is a scientific guess on what you expect to happen. Be specific with your hypothesis.
Variables • The variables are things you change to make the experiment fair. They are: • Controlled Variable: What are you going to control? • Independent Variable: What are you going to change? • Dependant Variable: What are you going to keep the same?
Apparatus & Method • Your apparatus is the equipment that you need for the experiment • Your method is a step by step instruction on what you are going to do in the experiment. • Your method should be able to be followed by someone not in your group!!
Equipment Setup & Risk Assessment • Equipment Setup is a drawing of how you are going to set up your experiment. It helps you think about what you are going to do. • Risk Assessment is where you write what dangers there are and what your doing to minimize or get rid of them.
Our Assessment Task • This is your most important assessment task in Science as it covers 3 criteria. Here is a breakdown on the main assessment tasks on Science: • Essay/Teaching Toolbox (Criteria A + B) • Test (Criteria C) • Design Task (Criteria D, E & F)
Our Criteria • Criteria D (Scientific Inquiry) – Research question, hypothesis, variables, equipment, method, suggests improvement to experiment, discusses errors in method etc. • Criteria E (Processing Data) – collect and present data such as tables and graphs, discuss the data, draw trends from the data, draws a conclusion from the results • Criteria F (Attitudes to Science) – works safely, can be independent, can work in groups, uses equipment competently.
What We Will Do! • Get into groups of 2 or 3. A group of 4 is unacceptable. If any group asks to be in a 4 (or larger), I will choose groups. • You will decide on an idea of Forces, Magnetism or Simple Machines that you want to look at. • You will design your own experiment – copying and pasting from the internet will get you a 0.
Our Timeline • This lesson, we will start by choosing an experiment. • You need to get permission from me before you start the write up. It’s not worth wasting time if you can’t do the experiment! • Your experiment must collect data. No data (length, force, time etc) = low Criteria E mark. • We will probably start the experiment after field studies.