# Shared Flashcard Set

## Details

Forces and Gravitation
The different forces applied in physics including the uses of 1st, 2nd, and 3rd laws.
71
Physics
11/19/2013

Term
 A force is a?
Definition
 A force is a push or pull.
Term
 What type of forces can be physically on an object?
Definition
 Contact forces
Term
 What are the three forces that can push or pull objects even though they are seperated?
Definition
 The three forces are gravity, electrostatic forces, and magnetism
Term
 What is the unit of force?
Definition
 Newtons or (N)
Term
 How many Newtons does it take to lift a one liter bottle?
Definition
 10N
Term
 When many forces are pushing/pulling an object, we can determine the?
Definition
 NET force
Term
 Forces going in opposite directions try to?
Definition
 Subtract from each other
Term
 Forces going in the same direction try to?
Definition
Term
 An arrow on a free body diagram is called a?
Definition
 A vector
Term
 What is Newtons first law of motion?
Definition
 An object at rest will remain at rest, and an object in motion will remain at motion, in a straight line, at a constant speed, unless acted upon by a NET external force.
Term
 The reason an object stops moving on earth is caused by?
Definition
 Friction.
Term
 The NET force on any unpowered moving object on earth is NEVER zero because?
Definition
 Friction always opposes it.
Term
 Friction does what?
Definition
 Friction creates an acceleration in the opposite direction of motion.
Term
 Once you are moving in space, what happens?
Definition
 You go in the direction, at that speed, forever.
Term
 The only way to make something move or change direction is to?
Definition
 Put an unbalanced force on it so the NET force is not zero.
Term
 Rockets only need their engines to do what?
Definition
 To speed up, slow down, or change direction.
Term
 When a NET force is placed on an object, what will the object do?
Definition
 The object will accelerate in the direction of the NET force
Term
 Whenever an objects state of motion is being changed, the object is?
Definition
 Accelerating
Term
 What two things determine how much an object will accelerate?
Definition
 The magnitude of the NET force and the inertia
Term
 What is inertia?
Definition
 Inertia is how much an object resists any change in motion.
Term
 A tennis ball has less ____ then a bowling ball
Definition
 Inertia
Term
 How much inertia an object has depends on its what?
Definition
 Mass
Term
 If you double an objects mass, you double its?
Definition
 Inertia
Term
 Mass is measured in what?
Definition
 Kilograms
Term
 What is Newtons 2nd law?
Definition
 Fnet=ma or a=Fnet/m
Term
 Newtons 2nd law says what?
Definition
 The bigger the NET force you put on an object, the larger its acceleration, and the bigger the mass of the object, the smaller its acceleration.
Term
 What does Newtons 2nd law allow you to calculate?
Definition
 The magnitude of the acceleration of any object (as long as you know the NET force acting on it.)
Term
 A newton is the NET force required to make a _ kilogram mass accelerate at 1m/s
Definition
 One
Term
 Every time an object pushes on a second object, the second object will?
Definition
 Push back with EXACTLY the same force, for EXACTLY the same amount of time, in the opposite direction.
Term
 Forces always come in?
Definition
 Pairs
Term
 You must give exactly the same push that you __ and get exactly the same push that you __
Definition
 Get, Give.
Term
 To walk, you must do what?
Definition
 You have to push the ground backwards in order to move forward. Then the ground MUST give you a push forwards
Term
 What is Newtons third law?
Definition
 For every action, there is an equal and opposite reaction
Term
 Any two objects will ___
Definition
 Attract
Term
 Gravity is described in?
Definition
 Isaac Newton's great Law of Gravitation
Term
 What is Newtons Law of Gravitation?
Definition
 Fg = Gm1m2/r2(squared) EXPLANATION: Fg is the force of gravity between them in Newtons. m1 is the mass of the first object. m2 is the mass of the secod object. r is the distance between the two objects. G is the "Gravitational Constant. It is equal to 6.673 x 10 (the the power of) -11 NM(squared)/kg(sqaured)
Term
 The graviational pull between two objects is directly related to the?
Definition
 It is directly related to the mass of the two objects.
Term
 The Law of the Gravitation also says that the gravitational pull between the two objects is inversly related to?
Definition
 the amount of distance between the two objects. (You double the distance, the pull is now 1/4. Triple it, and the distance is 1/9)
Term
 The Law of Gravitation explains what?
Definition
 How the solar system was formed
Term
 When you are standing on a planet, what is happening?
Definition
 The planet is pulling you in its own direction. But, all the forces are cancelling each other out, leaving you standing on the planet.
Term
 What is our weight on earth caused by?
Definition
 Earths gravity
Term
 Weight is a force equal to the mass of an object multipled by the?
Definition
 Acceleration due to gravity.
Term
 Why will your weight change as you visit different objects in outer space?
Definition
 Because the acceleration due to gravity is different on each object.
Term
 What is the symbol used to represent weight, or the force of gravity?
Definition
 Fg
Term
 Are weight and mass the same thing?
Definition
 HELLLL NO.
Term
 If you go to a planet where the acceleration due to gravity is different, your weight will change, but not your ___
Definition
 Mass
Term
 What is the only way to lose mass?
Definition
 The only way to lose mass is to lose atoms. (Chopping off your arm.
Term
 Weight is a force that is _____
Definition
 Always present (Even in outer space. =P)
Term
 Another kind of force on earth is a ___ force.
Definition
 Normal force.
Term
 When standing on the floor, you are not accelerating through the floor. This is because another force is acting upwards and cancelling out your weight. This is the force the floor is putting back on you, called a?
Definition
 Normal force.
Term
 Normal forces are always exerted ____
Definition
 perpendicular to the surface
Term
 A vertical surface would exert its normal force ___
Definition
 Horizontally.
Term
 A tile on a ceiling would exert its force ___
Definition
 Vertically downwards
Term
 What is the symbol for normal force?
Definition
 Fn (It's really a capital n, but it's below the F, and I can't do that on my computer. And this is NOT NOT NOT Fnet.)
Term
 When you are swinging an object in a circle, the object wants to do what?
Definition
 Go in a straight line
Term
 The direction and speed of the object put together are the objects what?
Definition
 Instaneous velocity.
Term
 The object will have a different what at every point in the circle?
Definition
 Instaneous velocity (Because the direction will be different)
Term
 To move in a perfect circle, you need what pointing perpendicular to the instaneous velocity?
Definition
 A force.
Term
 What is the force that points perpendicular to instaneous velocity called?
Definition
 A centripetal force. (This means center searching.)
Term
 Why do objects go in circles?
Definition
 Because something is forcing them to.
Term
 When you swing an object in a circle, the centripetal force is supplied by what?
Definition
 The tension in the string.
Term
 When an object is in a circular orbit around earth, the centripetal forcce is supplied by what?
Definition
 The earth.
Term
 A tight turn requires more ___ force than a more gradaul turne.
Definition
 Centripital force.
Term
 Centripetal forces are often described in terms of what?
Definition
 G's
Term
 If you are feeling a force equal to your own weight, you are experiencing _ G
Definition
 1
Term
 When you stand on the floor, you are not feeling your weight pressing you down into the ground, you're feeling?
Definition
 The normal force of the floor pushing you up.
Term
 A bathroom scale would change on the elevator because?
Definition
 The bathroom scale is measuring the normal force up from the floor, not your weight.
Term
 Falling objects caan't put any normal forces on what?
Definition
 Other falling objects.
Term
 When in a car, you're not feeling acceleration pressing you back in to your seat, you're feeling?
Definition
 The normal force on the back of your seat pushing you forwards.
Term
 When you feeling as though you are being pushed into a wall by an outside force, it is called a?
Definition
 Centrifugal force - THIS IS IMAGINARY!!!IT DOES NOT EXIST!
Term
 When you are spinning, you are not being pushed into the wall by an outside force, you are?
Definition
 Being pushed on by the wall. (The wall is pushing inwards into you.)
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