Can you solve these physics riddles? ft Simone Giertz - Part 1/3

TL;DR

A bicycle’s left-handed screw is on the left pedal, where its reversed threading helps keep the pedal from unscrewing while riding. Physics Girl host Dianna also challenges Simone Giertz with a terminal-velocity riddle involving equal-sized iron and wooden spheres, but saves the answer for Part 2. Read on for the setup, Simone’s reasoning, and the key facts revealed in Part 1.

Transcript

Hi, I'm Dianna. You're watching Physics Girl. And in this video, I have a super special guest. Her name is Simone Giertz. And I'm sure that you've seen her somewhere with her amazing, hilarious robots. Simone agreed to answer some physics riddles on this video. And I hope you're not mad about this because I know you love getting the answers right ... Read More

Key Insights

• "So I build robots that don't work really well." (0:44)
• "I build these like kind of useless machines as a way of entertaining people." (0:47)
• "On the pedal because when you pedal it can't unscrew itself." (1:46)
• "The answer is the left side. But the explanation as to why is actually not that straightforward." (2:35)
• "Which one experiences the higher force of air resistance, once the balls reach terminal velocity?" (3:16)

Questions & Answers

Q: Where is the left-handed screw on a bicycle?

It is on the left pedal, viewed from the rider’s perspective. Dianna confirms that the answer is the left side.

Q: Why does a bicycle pedal use a left-handed screw?

Simone reasons that the reversed thread keeps the pedal from unscrewing itself while someone pedals. Dianna accepts that warmup answer, although she says the full explanation is not straightforward.

Q: Who is Simone Giertz?

Simone Giertz is Dianna’s special guest on Physics Girl. Dianna introduces her through her amazing, hilarious robots.

Q: What does Simone Giertz make on her channel?

Simone describes her work as a strange mix of robotics and comedy. She builds robots that do not work very well and useless machines designed to entertain people.

Q: Did Simone Giertz study physics?

Yes, Simone studied physics in school. She says that she dropped out after one year, but the transcript does not explain why.

Q: What is the first physics riddle in Part 1?

Dianna describes two equal-sized spheres made from different materials, such as iron and wood, with one heavier than the other. After both are dropped from a very tall height and reach terminal velocity, the question is which sphere experiences the greater force of air resistance.

Q: Do the two spheres have the same size and surface?

Yes, the spheres are exactly the same size. Dianna also asks the viewer to imagine both have the same surface because they are coated with epoxy.

Q: Does Part 1 reveal the answer to the terminal-velocity riddle?

No, Part 1 only presents the riddle. Dianna tells viewers to return the next day for the answer and the next riddle.

Summary & Key Takeaways

• Dianna introduces Simone Giertz as a special guest who is known for her hilarious robots.

• Simone discusses her channel that focuses on building entertaining but useless machines.

• Dianna asks Simone physics riddles, starting with the location of a left-handed screw on a bicycle pedal.