Newton's Laws and the Winter Olympics: Part 1
With the Winter Olympics running at full steam, I’m sure you’ve all been thinking about Newton’s Laws of Motion. Every single event is just dripping with Newton’s Laws. Here’s how!
First, some background: Isaac Newton published a book a long time ago that described three laws of motion. A law is a description of how things work. These three laws describe all motion in the universe. We think. Usually. At least when things aren’t too big or too small.
Newton’s First Law of Motion is usually described along the lines of: an object at rest stays at rest, and an object in motion stays in motion at a constant velocity, unless acted on by an unbalanced force. In other words, things will keep doing what they’re doing unless we do something else to them.
Objects have inertia, which is the property of an object to keep doing what it’s doing. Some examples of this:
If you are roller skating and don’t know how to stop, you’re probably not going to stop until you hit the wall.
If you are walking across a flat surface and your foot gets stopped by an object, step, or piece of furniture, the rest of you will still keep going until it hits the floor.
If your car stops short, you will keep going until the seat belt stops you.
Usually, on Earth, an object that’s moving won’t be moving for very long, because there are so many unbalanced forces that can stop it: friction, gravity, the ground, a tree, or anything else.
The Winter Olympics are chock full o inertia, both as objects that want to keep moving and objects that want to change motion.
Speed Skating: When a race starts, skaters want to change their motion from stopped to moving, so they apply a whole lot of unbalanced forces in the form of skating strokes. Once they’re moving, they try to use that inertia to keep them moving, only moving when they need to change their velocity (either change direction or speed up after they’ve slowed down due to frictions unbalanced force working against them).
Figure Skating: Similar to speed skaters, figure skaters also use their blades to build up their velocity, but then need to apply a pretty strong unbalanced force if they want to change direction quickly. That’s why many figure skating jumps involve sticking the sharp pick at the front of the blade into the ice.
Alpine Skiing: When skiers are going fast, they want to do as little as possible to change that. When they need to turn, they need the edge of a ski and an impressive amount of muscular force to add that unbalanced force!
Curling: I’m still not exactly sure how curling works, but people seem very motivated to control exactly how much friction is acting on those stones to counteract the inertia from the initial throw.
Next time, we get to discuss F=ma, and how it relates to bobsleds.