Comparing The Load: The See-Saw As A Simple Machine
Balancing the Load: The See-Saw as a Simple Machine
Introduction
The see-saw is not just a playground toy, it is an example of a simple machine.
In physics, simple machines are tools that make it easier to do work. A lever is an example of a simple machine. A lever is a straight rod or board that pivots on a stationary point called a pivot point or a fulcrum. Levers are often used to lift heavy loads. A see-saw, a shovel, and a wheelbarrow are all examples of levers.
Abstract
Have you ever tried to pull out a nail out of wood with your bare hands? Or have you tried to shove a staple through a stack of papers without a stapler? A hammer's claw, a stapler, a pair of pliers and a shovel are each examples of everyday tools that use levers …show more content…
to make our work easier.
Objective
In this experiment, you will use a playground see-saw to investigate how a simple machine works. The objective is to learn the relationship between mass and distance when the see-saw is balanced and unbalanced.
Terms and Concepts * lever * fulcrum * mass * weight
Materials and Equipment * see-saw * tape measure * bathroom scale * one adult * two children of approximately the same weight
Experimental Procedure 1.
Determine the mass of each of the people participating in the experiment using the scale. (If your scale is calibrated only in pounds, you can convert to kilograms by multiplying by 0.454 kg/lb.) Record the mass of each participant in lab notebook. (For this sample procedure, we will refer to the participants using the following code: Adult=A, First child=C1, Second child=C2.) 2. Have C1 and C2 sit on the see-saw. Have C1 and C2 adjust their positions until the two masses are balanced. Measure the distance of each mass from the fulcrum. (Note: The distance should be measured along the side of the lever from the center line of the fulcrum to the center line of each mass. If your tape measure is calibrated only in inches, you can convert to meters by multiplying by 0.0254 m/in.) Record the data in your lab notebook (see the example data table below). 3. If one person moves closer to the fulcrum, what happens to the see-saw? Make a second data table like the example below for the see-saw when it is unbalanced. (Be sure to note which side of the see-saw is up.) 4. Have C1 and C2 get off the see-saw, and then repeat steps 2 and 3 four more
times. 5. Repeat the experiment (steps 2–4), but this time try to balance A and C1 or A and C2.
Sample Data Table: Level Balanced | Mass on Left
(kg) | Mass on Right
(kg) | Trial
(#) | Distance:
Fulcrum to Left Mass
(m) | Distance:
Fulcrum to Right Mass
(m) | Average Distance: Left
(m) | Average Distance: Right
(m) | Distance × Mass:
Left
(kg×m) | Distance × Mass:
Right
(kg×m) | (Mass of C1) | (Mass of C2) | 1 | | | | | | | | | 2 | | | | | | | | | 3 | | | | | | | | | 4 | | | | | | | | | 5 | | | | | | | (Mass of A) | (Mass of C1) | 1 | | | | | | | | | 2 | | | | | | | | | 3 | | | | | | | | | 4 | | | | | | | | | 5 | | | | | | |
Introduction
The see-saw is not just a playground toy, it is an example of a simple machine.
In physics, simple machines are tools that make it easier to do work. A lever is an example of a simple machine. A lever is a straight rod or board that pivots on a stationary point called a pivot point or a fulcrum. Levers are often used to lift heavy loads. A see-saw, a shovel, and a wheelbarrow are all examples of levers.
Abstract
Have you ever tried to pull out a nail out of wood with your bare hands? Or have you tried to shove a staple through a stack of papers without a stapler? A hammer's claw, a stapler, a pair of pliers and a shovel are each examples of everyday tools that use levers …show more content…
to make our work easier.
Objective
In this experiment, you will use a playground see-saw to investigate how a simple machine works. The objective is to learn the relationship between mass and distance when the see-saw is balanced and unbalanced.
Terms and Concepts * lever * fulcrum * mass * weight
Materials and Equipment * see-saw * tape measure * bathroom scale * one adult * two children of approximately the same weight
Experimental Procedure 1.
Determine the mass of each of the people participating in the experiment using the scale. (If your scale is calibrated only in pounds, you can convert to kilograms by multiplying by 0.454 kg/lb.) Record the mass of each participant in lab notebook. (For this sample procedure, we will refer to the participants using the following code: Adult=A, First child=C1, Second child=C2.) 2. Have C1 and C2 sit on the see-saw. Have C1 and C2 adjust their positions until the two masses are balanced. Measure the distance of each mass from the fulcrum. (Note: The distance should be measured along the side of the lever from the center line of the fulcrum to the center line of each mass. If your tape measure is calibrated only in inches, you can convert to meters by multiplying by 0.0254 m/in.) Record the data in your lab notebook (see the example data table below). 3. If one person moves closer to the fulcrum, what happens to the see-saw? Make a second data table like the example below for the see-saw when it is unbalanced. (Be sure to note which side of the see-saw is up.) 4. Have C1 and C2 get off the see-saw, and then repeat steps 2 and 3 four more
times. 5. Repeat the experiment (steps 2–4), but this time try to balance A and C1 or A and C2.
Sample Data Table: Level Balanced | Mass on Left
(kg) | Mass on Right
(kg) | Trial
(#) | Distance:
Fulcrum to Left Mass
(m) | Distance:
Fulcrum to Right Mass
(m) | Average Distance: Left
(m) | Average Distance: Right
(m) | Distance × Mass:
Left
(kg×m) | Distance × Mass:
Right
(kg×m) | (Mass of C1) | (Mass of C2) | 1 | | | | | | | | | 2 | | | | | | | | | 3 | | | | | | | | | 4 | | | | | | | | | 5 | | | | | | | (Mass of A) | (Mass of C1) | 1 | | | | | | | | | 2 | | | | | | | | | 3 | | | | | | | | | 4 | | | | | | | | | 5 | | | | | | |