Indian Rope Trick

This string appears to be held up by nothing at all!

The plastic pieces help to provide tension in the string, but where is the support coming from? All of these are otherwise flimsy materials

What is the maximum height that this string can stretch out to? What would your answer depend on?

Note by Chung Gene Keun
5 years, 6 months ago

No vote yet
1 vote

  Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

  • Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
  • Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
  • Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
  • Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list

  • bulleted
  • list

1. numbered
2. list

  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 2×3 2 \times 3
2^{34} 234 2^{34}
a_{i-1} ai1 a_{i-1}
\frac{2}{3} 23 \frac{2}{3}
\sqrt{2} 2 \sqrt{2}
\sum_{i=1}^3 i=13 \sum_{i=1}^3
\sin \theta sinθ \sin \theta
\boxed{123} 123 \boxed{123}

Comments

Sort by:

Top Newest

I agree with Pinak.

The plastic is in a deformed state and hence will tend to become straight.

It has been connected with the help of knots, the force that the plastic exerts on the knots will result in a tension in the rope.

The entire system can be thought of as a spring having some mass.

The maximum height will depend on the effective spring constant, (which will depend on the elasticity constant of the plastic and the string, if it is extensible) and the total mass.

Tanay Kibe - 5 years, 6 months ago

Log in to reply

Astute.

Fan Zhou - 5 years, 6 months ago

Log in to reply

The potential energy stored in the plastic when it is bent?

Just like a spring will support mass when compressed.

Pinak Wadikar - 5 years, 6 months ago

Log in to reply

9.8 metres....equilibrium of deformed string

Kevin Patel - 5 years, 6 months ago

Log in to reply

total height achieved should depend on the mass of the string, the stiffness of the plastic pieces.... .....oh, n the length of the string :)

Krishna Deb - 5 years, 6 months ago

Log in to reply

The stress generated in the plastic due to tensile force is providing the rope required tension.

Vineet Sharma - 5 years, 6 months ago

Log in to reply

spring constant

Nikeet Keshari - 5 years, 6 months ago

Log in to reply

Height depends on base .and the trick based on force against force.

vivek dobhal - 5 years, 5 months ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...