Lesson 2.7: Check Your Understanding

Answer questions 1 to 5 of Check Your Understanding on page 139 in your textbook.  Check your answers with those that follow.  Then answer the major question that follows the answers to questions 1 to 5. 

Question 1. A simple machine can make work easier by reducing the effort required to do the work.  

Question 2. Your diagram should be similar to this:

  

 Question 3. In a first class lever as shown in the answer to question 2, the fulcrum is between the effort and the load.
In a third class lever, the effort is between the fulcrum and the load.

 Question 4. The speed at which the axe head strikes the wood is important.  The faster the axe head travels, the more easily the wood will split.  The axe, along with your hands and arms, is a lever that is a distance and speed multiplier.  The longer the axe handle, the faster the axe head will travel.

 Question 5. You will have various possible answers.  The important thing to look for is that all your third class levers must be distance multipliers.

 Major Question:  For each of the three classes of levers, explain what happens to the effort, effort distance, and load distance when the fulcrum is moved, first towards the load, then away from the load.  Use diagrams in each case to support your explanation.

Check your answers with those that follow.

 

 

 

 

 

 

 

 

 

 

 

Answer to Major Question::

There are three classes of levers that must be explained.

                           

When the fulcrum is moved towards the load, the effort decreases, the effort distance increases, the load distance decreases.  This should be clear when you look at the following diagram.

When the fulcrum is moved away from the load, the effort increases, the effort distance decreases, the load distance increases.  This should be clear when you look at the following diagram.

                        

 

 

                           

When the fulcrum is moved towards the load, the effort decreases, the effort and load distances decrease by the same amount.  This should be clear when you look at the following diagram.

When the fulcrum is moved away from the load, the effort increases, the effort and load distances increase by the same amount.  This should be clear when you look at the following diagram.

 

 

 

 

                           

When the fulcrum is moved towards the load, the effort increases, the effort and load distances decrease by the same amount.  This should be clear when you look at the following diagram.

When the fulcrum is moved away from the load, the effort decreases, the effort and load distances increase by the same amount.  This should be clear when you look at the following diagram.


Now, do Assignment 7B.  Page forward to access the computer-scored assignment.