Thursday, September 25, 2014


Newton’s First law of motion
Newton’s first law states that an object in motion will stay in motion until acted on by an outside force, or that an object at rest will stay at rest until acted on by an outside force. This is a concept that cannot be displayed on earth as there are always outside forces acting on the objects. The most common forces are wind, gravity, friction, etc. The place where this concept can be see first-hand is in space. It would be quite amazing to throw a ball in space and never see it slow down.
Net Force
Net force is the total of the forces acting on an object. The amount of force that is placed on an object is measured in Newtons abbreviated (N). As an example if someone is pushing a box to the left with 10N of force, the net force of the box is 10N. If another person comes by and applies 10N of force to the right side of the box then the forces are subtracted from each other to find the net force. In this case 10-10=0, 0N in the net force of the box. Say another person walks by and adds 20N of force to the left side of the box, then the forces from each side of the box are subtracted. In this case 20+10=30N is the force on the right side of the box. The left side still only has 10N of force. So 30-10=20N of force is the net force of the box. Only the force that is applied opposite to the other force is able to be subtracted.
Equilibrium is the special case where the net force of the object is 0N. At equilibrium the object can be at rest, in motion, or at rest in motion. At equilibrium the objects forces are balanced and the object can be at constant velocity or constant acceleration.
Velocity is the speed that something travels. It is speed and the direction, it is NOT the same as speed. Velocity is normally measured in meters per second, abbreviated m/s. But velocity can also be measured in other increments as long as it is the measure unit of a distance over the time as in cm/s, mi/h, km/min, etc. When the velocity of the object remains the same it is referred to as constant velocity. Constant velocity has two formulas associated with it, these formulas only work for constant velocity. The first is to determine the velocity of the object is velocity=distance divided by time (v=d/t). The other is for finding the distance something has traveled at constant velocity it is distance =velocity multiplied by time (d=vt).
The acceleration of an object is the change in velocity in a period of time. Acceleration is measured by meters per second per second abbreviated m/s². Acceleration is not only forward it is also in reverse, when a car slows down it is accelerating in the opposite direction. Acceleration can be changing by either slowing down or speeding up, but when it stays at a constant there are two formulas that accompany constant acceleration. To find the velocity of an object a constant acceleration the formula is velocity =acceleration multiplied by time (v=at). The formula for the distance at a constant acceleration is the distance=one half multiplied by the acceleration multiplied by the time squared (d=1/2at²).
Using the graph
The graph equation y=mx+b is used in physics. It is mostly used in constant velocity and constant acceleration. The majority of the time the b value is about equal to 0, and all that remains is the y=mx. In the case for constant velocity the y=mx translates to d=vt, the slope m by itself translates to m=d/t. For constant acceleration the y=mx translates to d=1/2at², the slope m itself translates to m=1/2a. The slopes of the graphs are very useful to find the velocity and the acceleration.

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