Name:______________________________________________Date: __________

# Balancing Act: PHET

## Intro:

Play with the fire extinguishers and trash can. Sketch a model below of how you were able to balance all three of these items on the beam.

## Balance Lab

1. Click on "rulers" in the upper right menu. Place a 5 kg brick at each of the locations listed on the left side. Determine where a 10 kg brick much be place on the right side to blance the beam.

 Left Side (5 kg) --Distance from Center Right Side (10 kg) --Distance from Center .5 m 1.0 m 1.5 m 2.0 m

2. The data above should follow a pattern. Based on this pattern, how could you balance the 5 kg block if it was placed 4 meters from the center. Where would you need to place the 10 kg block?

3. Repeat this experiment with a 10 kg and a 20 kg block.

 Left Side (10 kg) --Distance from Center Right Side (20 kg) --Distance from Center .5 m 1.0 m 1.5 m 2.0 m

4. The data above should follow a pattern. Based on this pattern, how could you balance the 10 kg block if it was placed 10 meters from the center. Where would you need to place the 20 kg block?

5. A large man and a boy are pictured on the simulator (click on the arrow above the bricks.) Show on the diagram below where you would need to place the boy and the adult to balance the lever. You can use stick figures! b

6. Show where the young girl and the woman would need to be placed.

7. The next part will require you to use math to determine the mass of mystery objects. As you learned earlier, there is a pattern to how objects can be balanced on levers. This pattern can be illustrated by the following formula:

A 50 kg mass is placed 2 meters from the fulcrum. To balance the lever, a second object is placed 4 meters from the fulcrum. What is the mass of the second object? Show your work below!

8. A 10 kg mass is placed 3 meters from the fulcrum. At what distance would you need to place a 15 kg mass to balance the lever? (Show work!)

9. Scroll to the mystery objects. Use the bricks to balance each box and sketch your lever to include the distance each object was placed. Then use the formula above to determine the mass of each of the mystery boxes. Box A has been completed for you.

 Sketch the lever and where your placed the bricks for balance. Show your work using the formula. (M1 x a = M2 x b ) A M1 x 1 = 10 x 2 M1 = 20 B C D E F

10. Go to the GAME tab and play the level 1 game. What was your final score? _____ out of _____ | Time: ____

Play the level 2 game. What was your final score? ______ out of _____ | Time: _____