Friday, September 24

Blog three: Heads Up, We're Coming Down

"Talk to the hand."
This lunchbox part of a dramatic reenactment.

Pop quiz! What do you get when you combine my accident-prone friend, a metal lunch box, and a distracted high school student?

You get an announcement in the Daily Bulletin asking students to please stop putting things on the railing of second floor I-building.

Good times, man. Good times.

Alright, it wasn't really good times.

But, back to physics. The lunchbox was balanced on the railing while the absent-minded student was diddling about in her locker. She (while wearing her gigantic school-issued backpack) then backed up and it was all over bar the blood and out-freaking.

In other words, it was launched horizonally, which incidentally makes these numbers a lot easier to calculate!

There is no way this could possibly go wrong.
As we're all aware, the horizontal and vertical components of a vector may be treated separately. I have a tape measure, so let's get started.

We already know
initial vertical speed = 0 m/s
vertical acceleration = -9.8 m/s/s
and I went and found out that vertical displacement = -3.27 m

So now we can find out time because (say it with me, everybody!)
displacement = initial velocity*time + 0.5*acceleration*time*time

So time = 0.58 s

And we (and by "we" I mean "I," obviously) can then figure out the horizontal velocity using the same equation, because my tape measure says that the lunchbox went 0.80 m in the horizontal direction.

horizontal velocity = 1.38 m/s

Pretty good booty bump, yes?

And finally, we can find out the lunchbox's final vertical velocity (how fast it was going when it creamed her).

instantaneous velocity = initial velocity + acceleration*time

instantaneous vertical velocity = -5.73 m/s

She's going to want to put some ice on that.

PS: I used three pictures Ms C. Do I get, like, bonus points?