# Variation in throwing a ball

I might as well make a new tag called “basketball throws” because I can’t stop with the analysis of these crazy basketball shots. Watch – in the end someone is going to post a video about how all these were faked (and I have said there is no clear evidence they are fake). Oh, if…

# Density of Wood

This isn’t much – really it is part of another post I am working on. The point of this post is to calculate the density of this piece of wood. Really, there is a reason for this. I saw this little stick (sticklette?) and noticed that it was very cylindrically shaped. So, what if I…

# Pi: how many digits do you need?

The most basic explanation of Pi is that it is the ratio of the circumference to the diameter for a circle. That seems simple enough, but it turns out that Pi is an irrational number – so you can’t just write it down. Oh, I know that you are an uber-geek and you could recite…

# Science Fair for Mere Mortals

After judging the science fair last week, I would like to revisit my tips for you the science fair participant. Warning number 1 Some of the things I say here might go against what your teacher has told you. I am not sure what you should do in this case. Your teacher gives you a…

# RP 9: Error propagation and the distance to the Sun

Some time ago, I wrote about the awesome things the Greeks did in astronomy. Basically they calculated the size of the Earth, distance and size of the moon and distance and size of the sun. The value obtained for the distance to the sun was a bit off, but still a bang up job if…

# Uncertainty and Video Analysis

This is for commenter JimP. How do you take into account uncertainty when using video analysis? A great question. The first thing to think about is where does the uncertainty come from? My first guess would that it would be from the user. Where does the user click? Is it right on the object in…

# More projectile motion than you can shake a stick at

I don’t really know what that title actually means. So, I have been having problems with my PASCO projectile launcher devices. I will just call them launchers (they are really cannons). In my previous post, I looked at the launch speed from a launcher shot horizontally and vertically. The problem was that I was getting…

# More Measurements of the Projectile Velocity

The last time I looked at this projectile motion lab, I was confused. My different methods for measuring the launch speed of the ball were not even close to being consistent. So, I am bringing out the big guns – video. I made a video of the ball shot both horizontally off the table and…

# Uncertainty in measuring the launch speed

This is really a lab that I have students do, but I am pretty sure they don’t read this blog – so it is ok. If they are reading this, hi! We have these projectile cannons that shoot small balls. In order to look at projectile motion, they need to first determine the launch speed…