Newton's first 2 laws

Syntax

u2l1a1.gif

Overview

Newton's First Law states that an object in motion stays in motion unless acted upon by an equal or greater force. Also, an object in rest stays in rest unless acted upon by a equal or greater force.
The behavior of all objects can be described by saying that objects tend to "keep on doing what they're doing" (unless acted upon by an unbalanced force). If at rest, they will continue in this same state of rest. If in motion with an eastward velocity of 5 m/s, they will continue in this same state of motion (5 m/s, East). The state of motion of an object is maintained as long as the object is not acted upon by an unbalanced force. All objects resist changes in their state of motion - they tend to "keep on doing what they're doing."

Newtons_Second_Law_of_Motion.gif

Newton's Second Law states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. Which means that net force = mass*acceleration
Newton's second law of motion pertains to the behavior of objects for which all existing forces are not balanced. The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.

Equations

Equation One

-This supports LaTeX!

Kaitlin and Patti are accelerating a wagon at 2m/s/s. Each person is pulling with the same force in the same direction. If Kaitlin falls down and Patti continues to pull in the same way, the acceleration of the wagon will be?

Suppose that a sled is accelerating at a rate of 2 m/s2. If the net force is tripled and the mass is halved, then what is the new acceleration of the sled?

Applications of Newton's First law

u2l1a3.gif

There are many applications of Newton's first law of motion. Consider some of your experiences in an automobile. Have you ever observed the behavior of coffee in a coffee cup filled to the rim while starting a car from rest or while bringing a car to rest from a state of motion? Coffee tends to "keep on doing what it is doing." When you accelerate a car from rest, the road provides an unbalanced force on the spinning wheels to push the car forward; yet the coffee (which was at rest) wants to stay at rest. While the car accelerates forward, the coffee remains in the same position; subsequently, the car accelerates out from under the coffee and the coffee spills in your lap. On the other hand, when braking from a state of motion the coffee continues forward with the same speed and in the same direction, ultimately hitting the windshield or the dash. Coffee in motion tends to stay in motion.
Other applications of Newton's first law
*Blood rushes from your head to your feet while quickly stopping when riding on a descending elevator.
*The head of a hammer can be tightened onto the wooden handle by banging the bottom of the handle against a hard surface.
*A brick is painlessly broken over the hand of a physics teacher by slamming it with a hammer. (CAUTION: do not attempt this at home!)
*To dislodge ketchup from the bottom of a ketchup bottle, it is often turned upside down and thrusted downward at high speeds and then abruptly halted.
*Headrests are placed in cars to prevent whiplash injuries during rear-end collisions.
*While riding a skateboard (or wagon or bicycle), you fly forward off the board when hitting a curb or rock or other object which abruptly halts the motion of the skateboard.

External Links

Joke

image047.gif
Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License