March 29, 2019, 11:05am

The concept being displayed in the photo is buoyancy, more specifically Archimedes’ Principle. During my Scuba Diving excursion in Costa Rica, we visited some local reefs and went to depths of 70 ft. In order to travel that far under the surface, we needed to control our buoyancy. Archimedes’ Principle is that an entity that is completely or partially submerged in a liquid, in this case the ocean, is buoyed up by a force equivalent to the weight of the water displaced by the object. When in water, the weight of the volume of water displaced as compared to the weight of the diver's body and the diver's equipment, determines whether the diver floats or sinks. We used a button that inflated and deflated a flotation device in the back of our gear as shown in second and third sequences of the photo. We also made use of 3 sets of 3-7 pound weights to help the balancing process. In the first sequence of the photo, the divers are practicing creating neutral buoyancy, which is when they are able to swim through the water on a straight horizontal plain which is a very important safety skill for divers to know.

March 18, 2019, 4:47pm

The concept being displayed in this photo is the motion of a Projectile. Projectile motion is a type of motion experienced by an object that is thrown, or throws itself, on or near the Earth's surface. It moves along a curved path under the influence of gravity especially when the effects of air resistance are assumed to be a non factor. One way the bear is able to create as least air resistance as possible is by extending her arms and legs. This allows for a more aerodynamic position, allowing the bear to dive into the water with minimal disruption to the surface for a 400lb animal. This crescent path exhibited by the Polar Bear when it jumped into the water was proved by Galileo to be parabola shaped. The study of such motions is called ballistics, and the trajectory of the Polar Bear would be classified as ballistic trajectory. The only force of significance that acts on the Polar Bear is gravity, a downward force, which guides the bear on a downward acceleration. Because of the Polar Bear's inertia, no outside force is needed to maintain the horizontal velocity component of the object. This is how the Polar Bear observed at the San Diego Zoo is able to dive gracefully into the water.