### Balances and Springs

Balancing interactivity with springs and weights.

### Inside Outside

Balance the bar with the three weight on the inside.

### Balance Point

Attach weights of 1, 2, 4, and 8 units to the four attachment points on the bar. Move the bar from side to side until you find a balance point. Is it possible to predict that position?

# Swings and Roundabouts

##### Stage: 4 Challenge Level:

This text is usually replaced by the Flash movie.

$O$ is the centre of the balance, and $X$ is the position of the initially empty hook.

If you leave the hook at $X$ empty, what angle does $OX$ make to the vertical once the balance settles?

If you were to attach a weight of $1$ unit at $X$ , what do you think the angle might be?

Were you right?

If you were to attach a weight of $2$ units at $X$ what do you think the angle might be?

Right that time?

You only need the $1$ and $2$ unit weights for the problem set but the others are there to let you explore, conjecture and test - have fun.

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities can be found here.
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 10, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "github"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "english_confidence": 0.9410585761070251, "perplexity_flag": "middle"}