Challenge 3: Pull them together.

Challenge 3: Pull them together.

WALT made observations about effort and load.

Instructions:

1. Two people will hold a stick each vertically. Try to pull them together with one hand on each stick.
1. What simple machine could you use to help? A pulley
2. Use the simple machine to pull the people together.
1. How did you set up the simple machine? Make loops around the sticks
3. Change the system around and try again.
1. What do you notice? What do you need to do to make it easier?
2. Which set up was easier? The one with more loops
3. Which set up was harder? The one with only one loop

4. Conclusion: What is the trade-off? (What do you need to do to move a heavy object with little effort?) Put more than two loops.

Use this table to record your observations.

Changes in the simple machine.	Difficulty to move the sticks (easy/medium/hard).	Difficulty to hold the sticks apart (easy/medium/hard).
Make 5 loops	Easy	Hard
Make only one loop	Medium	Hard
Have no rope	Really hard	Easy

Task:

• Make an A4 poster / infographic about this challenge’s simple machine. Information it must have is:
• what the machine is used for
• how to make work easier
• what the trade off is

A4 dimensions:

29.7 cm x 21 cm