Bennett Science Blog

By Amber Bennett Have you ever wondered about the origins of the phrase, "get your ducks in a row"? What about how the "doggy paddle" works or why squirrels are such amazing jumpers? The answers to all of these questions have one thing in common: physics. Keep reading to learn about the science behind these three famous animal behaviors. How Do Squirrels Leap from Branch to Branch? A squirrel leaps through the air.  Photo Credit:  caroline legg ,  CC BY 2.0 , via  Wikimedia Commons The death-defying acrobatic maneuvers performed by squirrels look a lot like parkour tricks. But how do they know how to land tricky jumps between bendy tree branches that move with the wind?  Researchers say  it's a combination of learned behavior (practice makes perfect) and inherited adaptations.  To see what determines how far a squirrel is willing to jump and how the leaps are timed, researchers set up an obstacle course in an artificial forest. Then, they used peanuts ...

Credit: Public Domain By Andrew Bennett Collisions between objects are often treated using the conservation of momentum in physics . Energy can be tricky to deal with. We frequently have some amount of mechanical energy turning to nonmechanical energy, and it's difficult to predict how much. The collision causes atoms within the objects to shake, meaning they have kinetic energy (but we call it thermal energy when it's for individual atoms). This has taken away from the kinetic energy of the objects as a whole. It is not always clear how much of the original kinetic energy the objects will have after the collision. There is no such concern with momentum , so it is a useful way to understand these situations. Classes of Collisions However, we need to know about a few classes of collisions . The classes are divided up according to what is happening with energy in a particular situation. The classes are called elastic collisions, inelastic collisions, and completely (or t...

Credit: Public Domain By Andrew Bennett Conservation of Momentum Definition The conservation of momentum is enormously useful, particularly for learning about collisions between objects. Mostly used to describe the collisions of two or more objects, this physics principle means that the total momentum does not change in a closed system. In other words, the total value of momentum is constant when there are no external forces acting on a group of objects. Conservation of Momentum Equation Typically, we use an equation that comes from a special case of the Impulse-Momentum Theorem : When the force on the system is zero, the total momentum does not change. So, we can write an equation stating that the initial total momentum is equal to the final total momentum. This equation can be expanded by including momentum terms for each object. For example, if we have two objects labeled A and B , respectively, we might write this as: . We could also substitute the eq...