lab+report

[[image:file:///Users/user-kl653/Library/Caches/TemporaryItems/msoclip/0clip_image001.png width="521" height="157" align="right" caption="The Great Balancing Act"]]** Lever Lab ** Questions How is effort force affected when applied closer to the fulcrum?

Hypothesis: if the effort force is closer to the fulcrum then it will need more force to move the resistance force.

Variables: Dependant: the load. independent: fulcrum and effort force.

Materials: ruler, weight, pencil, GLX explorer

1. The smaller end of the meter stick will be for the load force. (The 0cm end). This means that the load you are trying to lift should be at this end. 2. The larger end of the meter stick (the 100-cm end) will be for the effort force. 3. Set up your lever like a meter stick with no weights, and the fulcrum close to the middle so the lever acts like a see-saw, balanced in the middle. 4. Put a load of 50 g at the LOAD END of the lever. Put the load as close as possible to the end of the lever. Be careful that the fulcrum stays in place. 5. Apply a force by pushing the Force Sensor down on the FORCE END of the lever. Add **//just//** enough to lift the load. 6. Record the newtons you need to lift the load. (I've done this one as an example below). 7. Repeat steps 4- 6 changing the Effort Force Distance. 8. Record the data in the data table.
 * Instructions: **

Fulcrum At (cm) || Load at End of Ruler (g) || Load distance (cm) (from fulcrum to load) || Effort Force needed (newtons) || Effort Force Distance (cm) || 50 || 100 ||  49 ||  1.0 ||  49 || 50 ||  100 ||  49 ||  1.5 ||  49 || 50 ||  100 ||  49 ||  1.6 ||  49 || 50 ||  100 ||  49 ||  1.4 ||  49 ||

Try these other fulcrum placements and find several effort placements that will work.

Fulcrum At (cm) || Load at End of Ruler (g) || Load distance (cm) (from fulcrum to load) || Effort Force needed (newtons) || Effort Force Distance (cm) || 40 || 100 ||  40 ||  0.3 ||  60 || 40 ||  100 ||  40 ||  0.6 ||  50 || 40 ||  100 ||  40 ||  3.5 ||  10 || 40 ||  100 ||  40 ||  1.2 ||  30 || 30 ||  100 ||  30 ||  <0.1 ||  70 || 30 ||  100 ||  30 ||  <0.1 ||  50 || 30 ||  100 ||  30 ||  0.5 ||  20 ||

1. Compare the effort distance and the effort force in all trials. What happens to the amount of effort force as the effort distance increases? Use the terms “inverse” or “direct” in your answer. 2. What class of lever did this represent? First class Extension Design a similar experiment using a lever of a different class. Do your results change are they similar? Hypothesis: if the fulcrum is moved further away from the resistance force, then the effort force would be greater than if it was closer. Variables: Dependant: fulcrum Independent: Effort force, load. Material: ruler, weight, pencil, GLX explorer Instructions: Place the fulcrum at 50cm on the meter stick Then place the resistance force (100g) at 100cm on the meter stick Now push down on the other end of the meter stick with your explorer and record your results. Now change the fulcrum to 40cm, apply the force on the same end of the stick Repeat these steps until your fulcrum reaches 0cm.