dot physics

Physics questions are the most fun when people don't immediately agree on the answer. What feels intuitive or obvious—sometimes isn’t. We can argue over the solution for hours of entertainment, and we might even learn something in the…

That expression doesn't look nice, but at least now the energy calculation is in terms of things that we actually know or can estimate. All we need to do is convert our estimates from imperial units to metric and we are all set. Using a…

Since the vehicle is moving up the incline and gravity only pulls straight down, there is a component of this force that pulls in the opposite direction as the velocity to make the vehicle slow down. As it moves up the incline, there is an…

If you want to be a Major League Baseball pitcher, you need to be able to throw a ball really fast—like 85 to 100 miles per hour. The faster the pitch, the less time a batter has to react and swing the bat, which means you have a greater…

There are three forces acting on the debris. First, there's the downward-pulling gravitational force (Fg) due to the interaction with the Earth. This force depends on both the mass (m) of the object and the gravitational field (g = 9.8…

If you drop an object, it will fall. It's a motion that we’ve all seen hundreds of times. We’ve also all seen plenty of the moon, which makes one complete orbit around our planet every 27.3 days (as seen from the Earth). Falling and…

Let’s say you don’t need to fly quite so far. What about a jet engine? These are the things you mainly see on commercial airliners, but very small jet engines can also be used to make a real-life jetpack.Just like rockets, jet engines…

I love this question from Youtuber Marques Brownlee, who goes by MKBHD. He asks: "What is a photo?" It's a deep question.Just think about how early black-and-white film cameras worked. You pointed the camera at, say, a tree and pressed a…

In this case, water starts from a source that's higher than the pump. (That's important.) As this input water moves down from the source, it increases in speed and goes out the waste valve. However, this moving water causes check valve A to…

There's your pi. In fact, you can measure the mass, period, and spring constant independently and use this to calculate pi just for fun.However, we can also use a mathematical function to represent this oscillation. Here is the simplest…