# Shared Flashcard Set

## Details

Ch 4 Dynamics Newtons Laws of Motion
Physics for Scientists and Engineers Chapter 4 Dynamic from 3rd ed Giancoli
24
Physics
11/04/2013

Term
 Newton's First Law of Motion
Definition
 INERTIA an object either is at rest or moves at a constant velocity, unless acted upon by an external force.   Objects keep doing what they are doing.
Term
 Newton's Sectond Law of Motion
Definition
 ΣF=ma Acceleration of a body is proportional to the net force acting on it and inversly proportional to the bodies mass.
Term
 Newton's Thrid Law of Motion
Definition
 When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body.   For every action, there is an equal and opposite reaction.
Term
 A packing crate slides down an inclined ramp at constant velocity. Thus we can deduce that
Definition
 a frictional force is acting on it.
Term
 You fall while skiing and one ski (of weight W) loosens and slides down an icy slope (assume no friction), which makes an angle θ with the horizontal. The force that pushes it down along the hill is
Definition
 W sin θ
Term
 A rope, tied between a motor and a crate, can pull the crate up a hill of ice (assume no friction) at constant velocity. The free-body diagram of the crate should contain
Definition
 three forces. F(tension), F(normal), F(gravity)
Term
 If two identical masses, attached by a massless cord passing over a massless, frictionless pulley of an Atwood's machine (at different heights), are released
Definition
 the masses will not move.
Term
 A train consists of a caboose (mass = 1000 kg), a car (mass = 2000 kg), and an engine car (mass = 2000 kg). If the train has an acceleration of 5 m/s2, then the tension force in the coupling between the middle car and the engine car is
Definition
 15,000 N (mass(caboose)+mass(car))*a=F(tension)
Term
 A decoration, of mass M, is suspended by a string from the ceiling inside an elevator. The elevator is traveling upward with a constant speed. The tension in the string is
Definition
 Note: constant speed = no opposing acceleration to (9.8 m/s/s)   so ma=mg   Answer =  equal to mg
Term
 A toolbox, of mass M, is resting on a flat board. One end of the board is lifted up until the toolbox just starts to slide. The angle θ that the board makes with the horizontal for this to occur depends on the [image]
Definition
 coefficient of static friction, μ.
Term
 our students perform an experiment by pulling an object horizontally across a frictionless table. They repeat the experiment on several other objects of different masses, always applying just enough force to produce the same acceleration. What does the graph (F/m) look like
Definition
 [image]
Term
 An object is placed on an inclined plane. The angle of incline is gradually increased until the object begins to slide. The angle at which this occurs is θ. What is the coefficient of static friction between the object and the plane?
Definition
 tan θ
Term
 A roller coaster car does a loop-the-loop. When it is upside down at the very top, What is the relationship between the F(normal) and the Weight (mg)
Definition
 The normal force and the weight are in the same direction.
Term
 A roller coaster car does a loop-the-loop. When it is right-side up at the very bottom, What is the relationship between F(normal) and Weight (mg)
Definition
 The normal force and the weight are in opposite directions.
Term
 A 0.5 kg (4.9 N) book rests on your desk. What is the reaction force to the 4.9 N weight (force) of the book?
Definition
 A 4.9 N force on the Earth.
Term
 You stand on a bathroom scale in an elevator accelerating upwards and it reads 200 Newtons. What force is the scale exerting on you?
Definition
 The scale exert a 200 N force on you.
Term
 During the investigation of a traffic accident, police find skid marks 90 m long. They determine the coefficient of friction between the car's tires and the roadway to be 0.5 for the prevailing conditions. To find the speed of the car you must know
Definition
 the acceleration of the car. The mass will cancel out of the equation. Review Chapter 4 in Giancoli.
Term
 An object moves left to right (right is positive) with speed decreasing at a constant rate and an accelertion of (+) or (-)
Definition
 its acceleration is negative.
Term
 A car pulls on a rope tied to a tree with a force of 1000 Newtons.What is the F(tension)
Definition
 A car pulls on a rope tied to a tree with a force of 1000 Newtons.
Term
 A 5 kg block and a 10 kg block slide down a frictionless incline. What is the relationship between their acceleration?
Definition
 they both have the same acceleration.
Term

## [image]

Definition
 A: 2/3 F total a:  F=3ma a = F/(3m)   Find H: Fh=2ma Fh= 2m(F/3m) Fh = 2F/3
Term
 what would the graph look like for The same horizontal force is applied to objects of different mass.
Definition
 [image]
Term
 Four students perform an experiment by pulling an object horizontally across a frictionless table. They repeat the experiment on several other objects of different masses, always applying just enough force to produce the same acceleration. What does the graph look like
Definition
 [image]
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