Motion, Forces, and energy
In this portion of physical science, we will investigate the basic laws of physics and apply them to the world. We will also spend time calculating and graphing motion and forces in the world around us.
Speed, Velocity and Acceleration
We often think that it is easy to tell if an object is in motion, but it becomes a lot more difficult if you think about that motion in relation to various reference points. Considering that our planet is in motion, nothing on the planet is ever truly still. If we choose a reference point that is generally accepted as still like the ground or a tree, we can calculate speed as the change in distance from the reference point per unit of time. Throw in direction and you have velocity. The rate at which velocity changes over a period of time is acceleration.
Speed, Velocity and Acceleration
We often think that it is easy to tell if an object is in motion, but it becomes a lot more difficult if you think about that motion in relation to various reference points. Considering that our planet is in motion, nothing on the planet is ever truly still. If we choose a reference point that is generally accepted as still like the ground or a tree, we can calculate speed as the change in distance from the reference point per unit of time. Throw in direction and you have velocity. The rate at which velocity changes over a period of time is acceleration.
Energy
Energy is everywhere and it is involved in everything we do. It is not only important in science, but plays a key role in economics and politics as well. The ways that we get and use energy have great and lasting impacts on our environment. All of this starts with a basic understanding of energy transformations and system waste.
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Newton's Laws of Motion
Isaac Newton is credited with writing three laws that describe how motion and forces act in the world.
Newton's First Law (the Law of Inertia) says that an object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an outside force like a push or friction.
Newton's Second law (F=MA) says that the acceleration of an object varies directly with the net force upon it and inversely with it's mass.
Newton's Third Law (forces in pairs) says that every force is accompanied by an equal force in the opposite direction. These two forces occur at the same time.
Isaac Newton is credited with writing three laws that describe how motion and forces act in the world.
Newton's First Law (the Law of Inertia) says that an object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an outside force like a push or friction.
Newton's Second law (F=MA) says that the acceleration of an object varies directly with the net force upon it and inversely with it's mass.
Newton's Third Law (forces in pairs) says that every force is accompanied by an equal force in the opposite direction. These two forces occur at the same time.
Simple Machines
Many of the tools that we use are based on one or more simple machines. A wheel barrow, crow bar, scissors, door handle or screw driver are all examples, but simple machines make up components of some of the more complex machinery in our lives as well such as the steering wheel in a vehicle, the blades of a lawn mower, or the pulley system on a crane.