80
Lesson 80 of 84 · Energy Transfer
ExperimentBalanced and Unbalanced Forces (Part 3)
What You'll Learn
Balanced forces are equal in size and opposite in direction, so an object stays still or moves at constant speed. Unbalanced forces cause an object to accelerate or change direction.
Key Words
- voltage
- current
- resistance
Materials Needed
- weights
- tape
- ruler
Safety First
- Keep small objects away from young children.
- Work in a well-ventilated area when using vinegar or other strong-smelling substances.
- Dispose of materials properly after the experiment.
Steps
Step 1 — Read
Read the introduction and identify the main idea of this lesson.
Step 2 — Do
Test friction: pull a weighted box across 4 surfaces (carpet, tile, sandpaper, foil). Use a spring scale to measure the force needed for each.
Step 3 — Observe
Look for patterns in your observations.
Step 4 — Record
Make a graph or chart showing your results.
Check Your Understanding
Question 1
1 of 3What do balanced forces result in?