International online physics competition

Sign up with a team of up to five.

97 registered teams from 16 countries
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.
What are the prizes?

We have rewards for the best of you.

T-shirts
and hoodies
Wolfram
Mathematica
software
Mugs
and towels
Orgpad
software
Canvas bags
We are discussing
other prizes
with our sponsors...
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 24 2021

Beginning of the contest

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

Hurry up!

Another series of problems appears, with problems related to different physics fields. For the next half an hour, participants can achieve bonus points for solving the series.

End of bonus points in the Hurry up! series

Problems from Hurry up! are still available but without bonus points.

End of the competition

The competition is over. We publish the author's solutions and settle potential conflicts.

Deadline for complaints

We close the possibility to complain and prepare to publish the official winners during the upcoming days.

Registration

Sign up and become a legend!

  • Participation is free for anyone!
  • Registration is open from October 4 until November 23, 12:00 CET.
  • Except for communicating with other teams, you can use any tools to solve the problems.
2020
One-Diraction
2019
\mathbb{H}armonic Approxilator
2018
e = pi = sqrt(g) = 3