# More on turning and braking

I can’t let it go. There is more here to explore. First, I can’t believe that I looked at braking and then turning but not turning then braking. And what about braking while turning? I will model braking and then turning – but it won’t stop here. Consider a few motions. I could turn and…

# Basketball shot – real or fake?

I have seen several videos similar to this. Real? Fake? How many tries did this take? Let the analysis begin. Before I do any analysis, let me state that I think this is not fake. I do not know that for sure, just my first guess. How would I tell if it is real or…

# How hot would the space jumper get?

A new video from the Red Bull Stratos Jump guys came out. Here it is: This reminds me of an unanswered question about the Stratos jump that I didn’t address on my last post on this topic. Commenter Long Drop asked about how much Felix would heat up as he falls from 120,000 feet. This…

# What could you do with 54,000 watts?

I already looked at ESPN’s Sport Science episode where they calculate that Marshawn Lynch produces 54,000 watts when pulling some tires. Yes, that is way too high. However, what would happen if some was actually that powerful? What could that person do? How fast could they run 100 meters? That is what I am going…

# The third leg of science??

I am sad to say the following comes from a school that I attended. This was from an alumni newsletter regarding the activities of one of the physics faculty. “Since the time of Archimedes, sciences advanced along two avenues, through new experiments and through theory….” I have a problem with just that first part, but…

# Modeling vs. Art

I have been reflecting on my recent failure to realize that the Giant Water Slide Jump was fake (more analysis here). I think the guys that made this video did a really good job on several levels. First, the motion appears to do two important things: shows constant acceleration in the vertical direction shows constant…

# Tides. Why are they so hard?

Every introductory astronomy text and most intro physics texts talk about tides. The usual explanation is something along the lines of: The moon exerts a gravitational force on the Earth and all the stuff on the Earth. This force decreases with distance (1/r2). Thus the moon pulls greater on one side of the Earth than…

# Balancing sticks – choose a longer stick

Maybe you have seen this trick. Basically, you hold by supporting it with two fingers from the bottom. You then move your hand around to keep it balanced while the stick is vertical. It is really not as hard as it looks. Also, there are two things that can make your job easier. Use a…

# A note about numerical calculations

[In a previous post, I talked about numerical calculations](http://scienceblogs.com/dotphysics/2008/10/basics-numerical-calculations/). The basic idea is to use the momentum principle and the following “recipe”: Update the position of the particle Update the momentum of the particle Update the force on the particle Looks great, right? Well, it mostly is great. I want to give a couple of…

# Basics: Numerical Calculations

**Pre Reqs:** [Kinematics](http://scienceblogs.com/dotphysics/2008/09/basics-kinematics.php), [Momentum Principle](http://scienceblogs.com/dotphysics/2008/10/basics-forces-and-the-momentum-principle.php) What are “numerical calculations”? Why are they in the “basics”? I will give you really brief answer and then a more detailed answer. Numerical calculations (also called many other things – like computational physics) takes a problem and breaks into a WHOLE bunch of smaller easier problems. This is great…