Lever position and effort

### ZIMSEC O Level Combined Science Notes: Experiment: Lever position and mechanical advantage

Aim: To show that mechanical advantage depends on lever position

Materials: 1m rectangular poplar wood pieces, string, measuring tape, weights, clamp

Method

1. Cut a grooves at 20cm, 40 cm and 50 cm lengths from the right hand end of one of the popular wood pieces
2. Loop a string on the 50 cm(half way) groove and suspend the piece of wood
3. Attach 10g weights on each end of the piece of wood until it is in balance. You will need to experiment to find the number of masses required to balance the piece of wood
4. Plot the results in a table showing pivot position, left side (effort) and right side (load) masses
5. Repeat the experiment by moving the pivot string closer and closer to the end i.e 40cm and 20 cm grooves

Observation and Results

• Less effort is required to lift the load when the lever is moved to the 40cm and 20 cm positions
• When the lever is on the 50cm mark (the center) the load is equal to the effort

Conclusion

• Less effort is required when the lever is moved closer to the load
• The effort moves a greater distance when the lever is moved closer to the load and away from the center

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