A Physics Evaluation of Tesla’s Shattered Cybertruck Home windows

I do not know what to consider Elon Musk anymore. I imply the SpaceX stuff is superior, and the Tesla automotive has been fairly cool. However now we’ve got the Tesla pickup truck, unveiled on Thursday. (Simone Giertz did it first!) The Tesla Cybertruck seems to be odd—one individual likened it to a futuristic doorstop—however that is fantastic with me. My drawback is with the disclosing itself.

In case you missed it, Musk wished to display the truck’s ruggedness. They begin off by hitting a traditional truck door with a sledgehammer. Sure, it makes a dent. What concerning the Tesla truck? Bam! Not a scratch. It has a thicker metal exterior that makes it impervious to individuals with sledgehammers.

Oh, and the home windows? They’re product of “Tesla Armor Glass.” To check, Musk’s assistants drop a steel ball on regular automotive glass, which cracks. Then they drop it on Tesla’s particular glass, and the ball bounces off. They drop a much bigger ball on it from larger up. Nothing. So the man tosses the ball on the driver’s window of the Cybertruck—and smashes it.

“Effectively, possibly that was a bit of too onerous,” Musk says. So the man picks up the ball and lobs it as softly as he can on the rear passenger window. Now there are two smashed home windows. Awkward.

I don’t know, if it have been me, I’d have examined this demo earlier than doing it reside onstage. However, to Musk’s credit score, they only carried on with the present. The entire remainder of the presentation was carried out in entrance of a prototype with damaged home windows. Unhealthy optics, however it’s important to admire his aplomb.

What went flawed? Why did Tesla’s fancy glass survive a dropped ball however not a thrown ball? To seek out out, we want some physics.

How excessive was the take a look at ball dropped?

When you drop a steel ball, it accelerates because it falls. So to know the way onerous it hit the glass within the demo, we have to know the peak from which it was launched. For the primary drop, the stage assistant stands over the glass, raises his arm, and releases the ball—that appears to be a distance of roughly 1 meter. The upper drops are a bit of trickier. It will have been good if they only informed us, however that’s OK, we are able to estimate it from the period of time it takes to hit.

When you drop an object, it begins with an preliminary velocity of zero, and the one drive performing on it’s gravity. The gravitational drive, we all know, will depend on the native gravitational subject (9.8 newtons per kilogram) and the mass of the thing.

We additionally know that the web drive should equal the product of mass and acceleration. Discover: Mass is on either side of the equation, so we cancel out the mass, and we get that the acceleration of a falling object is 9.8 meters per second squared within the downward path.