Motion and Related Concepts Flashcards
What are the physics concept of motion?
F=Gm1m2/d2
F is the force of gravity, G is a constant (the Gravitational Constant) which can be measured, m1 and m2 are the masses of the two objects (earth and apple or earth and moon, in the above text), and d is the distance between them. You can see that gravity follows the famous inverse square law that many physical phenomena follow.
One consequence of all this is that everything attracts everything else with gravitational forces. The earth attracts the apple and the apple attracts the earth with the same force. The apple is the one that moves noticeably because it is so much lighter (and easier to move) than the earth. The earth and a ten pound weight are attracted to each other with a force of exactly ten pounds. In fact, that is the definition of weight, the force of gravitational attraction. Everything attracts everything, hence the “universal” in the name of Newton’s law. And the law holds way out as far as telescopes can see; it is truly universal.
Two bodies, M1 (mass one) and M2 being attracted together. R represents distance between them. Gravity and pull is equal to one another
* One or both of the mass increases, the overall value, gravitational force is greater between them.
As you increase the distances, the force gets less and less. because it is squared, things happen much more quickly.
BASICALLY - mass makes gravity force greater
distance makes gravity force less.
What are two important laws of GRAVITY?
remember F = G (m1 m2 / d2)
1. The more massive either or both bodies are, the greater the gravitational force between them.
- The further apart the two bodies are, the lesser the gravitational force between them.
The earth is so much closer to the moon, so it orbits the earth, not the sun. We orbit the sun because its so big.
What is motion?
motion is defined as a change in position (you start at a place and end up somewhere else)
UNLESS the object is moving in a vacuum (no movement), the object causes displacement (like when your running, wind shifts around you, displacing air)
What is speed?
The objects rate of motion.
what’s the equation for distance, speed, and time questions?
speed= distance/time
What is velocity?
velocity describes speed and direction ( 6 miles an hour east = velocity.
Velocity is often represented as using a vector. (drawn as a little arrow with the speed.)
What is acceleration?
a CHANGE in velocity (Deceleration is also acceleration, speeding up in the other direction.
WHEN GRAPHING ACCELERATION
When we have acceleration, we will have a curved line. If there was no change, it would be a straight line. By how faster they go, the more steeply inclined the line would be. the slower, the less steep the line.
**When you are traveling and graphing the line, and you go back to where you started, the distance WILL NOT GO back down the line. that is meant to trick you. You are still traveling.
What is Newton’s first law of motion?
The law of Inertia
- an object in motion (or at rest) stays in motion along a straight path (or at rest) UNLESS acted upon by an external force.
ex: astronaut with glove in outer space.
What is the second law of motion?
The Law of Acceleration
Force= Mass x Acceleration
Which generates more force? multiply together 1 pound going 80 or 15 going 10 80 versus 150 You do not want something 15 pounds going at you ten miles an hour versus something 1 pound going 80mph
What is the 3rd Law of motion?
The Law of Reciprocal Action
For ever action, there is an equal and opposite reaction
ex: running into a wall and falling backwards.
What are other forces that change motion?
- Gravity- the bullet being shot and dropped by hand hit the ground at the same time
- Magnetism- why a compass points north, magnetic pull
- Friction- forces (or friction) resistance
