In physics, dynamics is the study of forces (why objects move). When studying dynamics, vectors are used to describe forces. Vectors are often identified with arrows. The longer the vector is, the stronger the force is.
When vectors are collinear, the magnitudes are simple added while keeping the direction. When the vectors are not parallel, simply subtract the smaller magnitude from the larger and use the direction of the longer. Vectors can also be described using components (x part, y part). The components of a vector are two perpendicular vectors that would add together to yield the original vector: - Components are notated using subscripts.
When finding the resultant vector using vector components, square, sum and square root the components. To find the angle, take the inverse tangent of the y component over the x component. When vectors are not parallel or perpendicular, the only way to add the vectors is by drawing a scale diagram. To algebraically resolve vectors, use the Pythagorean theorem, break them down into x and y components, add x to x and y to y, find the magnitude and finally find the direction using tan-1(y/x). When a vector has an equivalent magnitude to that of the resultant but facing the opposite way, the forces are at equilibrium.
Newton's Laws Newton described force as the ability to cause a mass to accelerate. -Newton's first law states that an object in motion will stay in motion unless a force is applied. -Newton's second law states that Force Quantity is equal to mass multiplied by the acceleration (F=ma). -Newton's third law states that for every action, there is an equal but opposite reaction.
- Newton's first law deals with inertia. Inertia is a property of matter that resists acceleration and depends only on mass.
Summary -Forces cause acceleration and have the ability to cause acceleration. -If an object is accelerating, the Net Force is not zero. -To find the Net Force, take the vector sum of all component forces -To find the acceleration, use the equation Fnet=ma. -If forces act at angles, trigonometry is needed to solve. [Fx=Fcos(0)]
[Fy=Fsin(0)]
-If forces act along the axes, no trigonometry is needed to solve.
References
 |
This physics-related article is a stub. You can help Wikipedia by expanding it. |
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
