November 20, 2024, 5:00 - 8:00 p.m. CET

International
Online
Physics Competition

About Solutions Results list

Problem 14

Apology for Translation Error

We regret to inform you that there was a mistake in the translation of Problem 14. We sincerely apologize for any inconvenience this may have caused.

To address this issue fairly, we will cancel any penalties for incorrect answers to this problem until 18:11 CET.

Thank you for your understanding and for competing!

Competition results

How were the teams doing?

Rules briefly

What is Physics Brawl Online?

Up to 5 high school students compete from home in a 3-hour long contest in solving physics problems.

There are 7 problems available for you. As soon as you solve one, you get another problem immediately. For each solved problem the team is awarded with points.

The best teams win prizes and undying glory in our competition, which has been held annually for over a decade now.

Rules

What are the prizes?

We have rewards for the best of you.

FYKOS's bottles,
T-shirts and other prices Wolfram
Mathematica
software

Factorio licenses Diamond membership on
Orgpad

Board
and card
games

License to
Avast

Problem examples

Everyone finds suitable difficulty.

A coniferous tree could be (from a mechanical point of view) approximated by a homogeneous right circular cone with height h = 40 m and radius at the base r = 1.0 m. Find the maximal angle by which its axis may be displaced from the vertical axis before it starts to fall due to its weight.

A h = 30 m high waterfall has flow rate Q = 1,2 m³·s^-1. Find the total force with which water impacts the ground under the waterfall. Assume that the water quickly flows away from the point of impact and the depth of water under the waterfall is negligible.

Find the resistance between two neighbouring vertices of a four-dimensional cube made of wire. Each edge of the cube has a resistance R = 1 000 Ω.

Vítek would like to get some water from his well, but he does not want to keep pulling the bucket up. Therefore, he gradually stirred the water around faster and faster until, at an angular velocity ω = 11 rad·s^-1, the water started flowing out of the well all by itself. Vítek knows the depth of the well (from the top edge to the ground at the bottom) h = 47 m. The well has a circular cross-section with a radius r₀ = 1,6 m. What was the height of the water column (from the bottom of the well to the water surface) before Vítek started spinning the water around?

Competition schedule

The contest takes place on Wednesday November 20, 2024

Beginning of the contest

Participants get 7 problems. Once they solve any of them, they immediately get another.