SNL "Posters" - Marcello Hernández was cheated

"Posters" has been a recurring skit on Saturday Night Live. It originally featured guest Emma Stone and cast member Pete Davidson, with additional cast members Mikey Day, Kenan Thompson, and Kate McKinnon. It seems to be resurrected whenever Stone hosts.

Last night, "Posters" was staged again, this time with Marcello Hernández and Ego Nwodom alongside Stone, Day, and Thompson. The talking posters assured Hernández that physics was—in fact—relevant.

The punchline stinger at the end of the skit is always a graphic showing the subsequent failed exam.

I posted the skit to Twitter/X (@phyzman) for the benefit of my #ITeachPhysics colleagues. Dan Burns (@kilroy22) quickly noticed that Marcello actually got the correct answer on the most difficult question of the three shown, Question 3.

The recoil height depends on the ball's recoil speed. Conservation of momentum for a perfectly elastic head-on collision with a twice-as-massive body is 1/3 of the impact speed. With 1/3 the impact speed, conservation of energy reveals the ball will rise 1/9 the launch height: 1/9 h. Marcello's answer is correct.

That made me take a look at Question 2. The road must exert a forward force to match the force of air resistance while also exerting a centripetal force equal to mv²/r. Taken together, the forward force and radially inward force result in F(B). Marcello's answer is correct on that one, too.

Dan and I dismissed Question 1 as "not even wrong" since it's not even a physics question. It's a pure math question involving unit conversions. Invoking Avogadro's number in a physics exam is distasteful. 

If we allow this faux pas, 1/12 of Avogadro's number is 5 × 10²². Convert that from seconds to hours by dividing it by 3600 (the number of seconds in an hour). Convert that to days by dividing by 24. Convert that to the never-used-in-a-physics-class unit of weeks by dividing by 7. That's 8.26 × 10¹⁶ weeks. Not an option. So divide that by 52 to convert it to years. 1.59 × 10¹⁵. Once again, Marcello's answer is correct.

It's picking nits to complain that the formatting of Question 1's answer options don't match those of Questions 2 and 3. Or that X was used instead of the correct symbol, ×.

Marcello aced this exam. Kudos to the talking posters. And who is Marcello's physics instructor?

PSSC Film Archive posted on Reddit

In retirement, I find moments of serendipity from time to time. While meandering the Interwebz looking for the source material used in a lesson on electric field lines, I came across a Reddit post by user SchoggiToeff. They compiled a list of films produced for the Physical Sciences Study Committee (PSSC) in the Cold War era that have survived through to the Age of YouTube (and The Internet Archive).

PSSC Films Available on the Internet

The Physical Science Study Committee (PSSC) Films are a set of 53 films made in the late 1950 early 1960 for US high school physics. The films are also referenced in the Berkeley Physics Course, of which the 2nd book is the well renowned Electricity and Magnetism by Edward M. Purcell.

While dated, the films are still educational and can bring some insight in various physical observations and phenomena. I personally like the Frames of Reference film.

Unfortunately I could not find all of the films, thus the gaps. If you know other ones, please leave a comment. On the Internet Archive one can also find Italian dubbed versions. [u/SchoggiToeff on Reddit r/Physics.]

Impressive work! And a great way to while away an afternoon, checking out these old classics. Clips from many of these were restored and digitized around 1990 and released as Ztek's Physics: Cinema Classics (P:CC). P:CC included clips from a host of other sources, too. It appears that project has gone dormant. I had P:CC on LaserDisc, and then on DVD, when I was still in the classroom.

Here's one of the classic treasures you can find on the Reddit list. A popular favorite among physics instructors of a certain age.