Force and Motion
5.P.1 Understand force, motion and the relationship between them.
Newton's Three Laws
Newton's 1st Law of Motion
*An object tends to stay at rest and an object tends to stay in motion with the same speed and in the same direction unless acted on by an unbalanced force.
* Objects tend to keep doing what they are doing.
* If the forces acting upon an object are balanced, the acceleration of that object will be zero (no motion).
*also known as the "law of inertia"
Newton's 2nd Law of Motion
* Acceleration is always in the direction of the unbalanced force.
*If you want something to accelerate faster, you need to decrease its mass.
* Acceleration of an object depends upon two variables-the net force acting upon the object and the mass of the object.
* Force = mass x acceleration or F = ma
Newton's 3rd Law of Motion
*Explains why forces act in pairs.
* For every action, there is an equal and opposite reaction.
* When one object exerts a force on a second object, the second object exerts the same amount of force back on the first object (but in the opposite direction).
* Equal forces acting in opposite directions create a net force of zero.
* Action and reaction forces are equal forces acting in opposite directions. The reason they can't cancel each other out is because they are acting on different objects.
acceleration: rate of change in velocity
distance:how far an object travels
force: any push or pull on an object
friction: force that resists motion between two touching surfaces; acts in the opposite direction of the force; can be useful or wasteful
inertia: the tendency of an object to resist a change in motion or keep doing what it is doing
Note: the greater the mass of an object, the greater the inertia
kinetic energy: energy of motion (moving ball going down a ramp)
mass: how much matter an object contains
momentum: force or speed of movement; mass in motion, example: a moving train has much more than a moving soccer ball
motion: an object changing position over time; change in position is measured by distance and time
potential energy: stored energy (ball positioned at the top of the ramp)
velocity: speed with direction (example: 45 mph northeast)
Physical and Chemical Changes
Questions to Consider: