# Shared Flashcard Set

## Details

Physics Final Sem. 1
Units 1-12 Vocabulary, Formulas, all that jazz.
149
Physics
12/12/2009

Term
 Name the steps of the scientific method in order.
Definition
 1. Observation 2. Question 3. Hypothesis 4. Prediction 5. Experiment 6. Explanation
Term
 A scientific theory is...
Definition
 a well tested explanation that may be revised as new evidence is discovered.
Term
 The synthesis of several hypotheses that have been tested but never proven to be false is called a...
Definition
 theory
Term
 Which of the following statements about technology is NOT true? a. answers questions b. solves practical problems c. seeks to create, design, build d. puts science to use through tools
Definition
Term
 As an object falls freely (in the absence of air resistance) it a. velocity increases b. acceleration increases c. both a and b are correct d. none are correct
Definition
 a. velocity increases
Term
 A quantity divided by time is a ______.
Definition
 rate
Term
 Motion along a straight-line path is called _______ motion.
Definition
 linear
Term
 Motion is relative to the _________ of the ______.
Definition
 surface earth
Term
 When we say something is in respect to, we mean it is _________ to.
Definition
 relative
Term
 Define speed.
Definition
 A measure of how fast something is moving.
Term
 Define instantaneous speed.
Definition
 speed of an object at any instant
Term
 Define velocity.
Definition
 The speed of an object in a given direction.
Term
 What is the difference between speed and velocity?
Definition
 Velocity, in addition to measuring speed, measures it in a specific direction.
Term
 Give the formula for speed.
Definition
 Speed = distance divided by time   s=d/t
Term
 Give the formula for acceleration.
Definition
 change in velocity/ change in time   a=(c)v / (c)t
Term
 Give the formula for final speed.
Definition
 Vf = Vi + at
Term
 Give the formula for average speed.
Definition
 vi + vf 2
Term
 What is the force of gravity?  (answer is a number)
Definition
 9.8 m/s2
Term
 Give the formula for the instantaneous speed of a falling object.
Definition
 v = vi + gt
Term
 Give the formula for vertical distance fallen.
Definition
 d = 1/2gt2
Term
 Give the formula for horizontal distance traveled.
Definition
 d = vt
Term
 A water balloon is dropped from a second story window. What is the speed of the water balloon after 2.5 seconds? What is the average speed of the water balloon after 2.5 seconds? How far has the balloon fallen in this amount time?
Definition
 speed → (19.6+29.4) 2 av. speed → vi+vf  2   distance fallen → d= 1/2gt2 d=1/2(9.8)2.52 d=12.25
Term
 non-linear motion
Definition
 motion along a curved path
Term
 An airplane is flying 200 km/h north. If it flies directly into a 50 km/h... TAILWIND, what is its speed? HEADWIND, what is its speed?
Definition
 TAILWIND= 250 km/h HEADWIND= 150 km/h
Term
 A vector is a quantity that has _____ ___________ and direction.
Definition
 both magnitude
Term
 A scalar is a ________ that has ___________ only.
Definition
 quantity magnitude
Term
 When representing velocity as a vector, the length of the vector represents the __________ of the __________.
Definition
 magnitude velocity
Term
 You throw a ball straight up into the air with an initial speed of 20 m/s. What is the ball's acceleration at the highest point in its trajectory?
Definition
 9.8 m/s2
Term
 One Newton is equal to 1...
Definition
 kg m/s2
Term
 An object that has a WEIGHT of 9.8 N has a mass of: a. 10 kg b. 9.8 kg c. 0.1 kg d. 1 kg
Definition
 d. 1 kg
Term
 It is just as hard to push a car on the moon as it is to push the same car on earth because the _____ of the car is ______________ of _________.
Definition
 mass independent gravity
Term
 An object that has a mass of 20 kg has a weight of a. 196 N b. 19.6 N c. 1.96 N
Definition
 a. 196 N
Term
 Give the formula for acceleration.
Definition
 change in velocity     time interval   a=v/t
Term
 What is the cause of acceleration?
Definition
 Force.
Term
 The combination of forces acting on an object is the ___ _____.
Definition
 net force
Term
 Acceleration is ________ proportional to ___ force.
Definition
 directly net
Term
 If the force on an object doubles, the acceleration _______.
Definition
 doubles
Term
 For a given force, the acceleration produced is ______________________ ________________.
Definition
 inversely proportional to the mass.
Term
 Define inversely proportional and give an example.
Definition
 The two values change in opposite directions.   Example: If the force is 3 N, the acceleration will be 1/3 m/s2.
Term
 What units do we use for force, weight and acceleration?
Definition
 force= Newtons weight= kg acceleration= m/s2
Term
 ______ was the first to realize that the acceleration produced when we move something depends not only on how hard we push or pull, but also on the object's ____.
Definition
 Newton mass
Term
 Give this chapter's formula for acceleration.
Definition
 a=f/m
Term
 Liquids and gases are called _______ because they both flow.
Definition
 fluids
Term
 Define air resistance.
Definition
 the friction acting on something moving through air
Term
 A diagram showing all the forces acting on an object is called a ________ _______.
Definition
 free-body diagram
Term
 Pressure is...
Definition
 the amount of force per unit of area.
Term
 We measure pressure in _______, which is newtons/sq.m.
Definition
 pascals (Pa)
Term
 When an object stops accelerating, it has reached its _________ _____.
Definition
 terminal speed
Term
 Define terminal velocity.
Definition
 terminal speed with the direction of motion
Term
 Give the formula for force.
Definition
 f=ma
Term
 Friction is the force due to surface ______________. It is caused by two objects rubbing _______ each other.
Definition
 irregularities against
Term
 Acceleration is _______________ to force and _________ proportional to mass.
Definition
 proportional inversely
Term
 There is higher resistance at higher ______.
Definition
 speeds
Term
 Constant velocity in presence of friction occurs when the applied _____ is equal to force of _________.
Definition
 force friction
Term
 The short formula for pressure is...
Definition
 p=fa
Term
 The units for pressure are ________.
Definition
 N/m2
Term
 If action and reaction forces are ________ to the system, they cancel each other and produce no ___________ of the system.
Definition
 internal acceleration
Term
 Action and reaction forces do not ______ each other when either is external to the _______ being considered.
Definition
 cancel system
Term
 A wagon that is moving at a constant velocity has a net force a. greater than the force of friction b. equal to the force of friction c. equal to the weight of the object d. equal to zero
Definition
 d. equal to zero
Term
 As mass increases, acceleration ____________.
Definition
 decreases
Term
 Compared to the acceleration of the car, the acceleration of the bug after striking the windshield is...
Definition
 larger.
Term
 When a soccer ball is kicked, the action and reaction forces do not cancel each other out because...
Definition
 they act on different objects
Term
 Newton's Third Law says...
Definition
 whenever one object exerts a force on another object, the object pushes back with the same force.
Term
 A force of 3 N accelerates a mass of 3 kg at the rate of 1 m/s2. The acceleration of a mass of 6 kg acted upon by a force of 6 N is...
Definition
 the same.
Term
 A rocket is able to accelerate in the vacuum of space when it fires its engines. The force that propels the rock is the force of the _________ ______ on the ________.
Definition
 exhaust gases rocket
Term
 What does momentum refer to?
Definition
 inertia in motion
Term
 Give the formula for momentum in words.
Definition
 momentum= mass times velocity (or speed)
Term
 Write the formula for momentum.
Definition
 p=mv   where p refers to momentum, m is mass, and and v is velocity.
Term
 The formula for impulse is:
Definition
 Ft=mv
Term
 Impulse is _______ times _____ __________.
Definition
 force time interval
Term
 Impulse = change in ___________.
Definition
 momentum.
Term
 Impulse is _______ force times ______.
Definition
 impact time
Term
 Impulse is measured in __.
Definition
 Ns (newton-seconds)
Term
 Impact refers to a _____ and is measured in ________.
Definition
 force Newtons
Term
 Define impact time.
Definition
 The time in which momentum is brought to zero.
Term
 Impulses are greater when an object...   (hint: BOING!)
Definition
 bounces. More impulse is required for an object to bounce than to simply stop moving.
Term
 The law of conservation of momentum states that...
Definition
 In the absence of an external force, the momentum of a system remains unchanged.
Term
 If no ___ force or net _______ acts on a system, the momentum of that system _______ change.
Definition
 net impulse cannot
Term
 When a quantity in physics (such as momentum) does not change, we say it is _________.
Definition
 conserved
Term
 When objects collide without being permanently deformed and without generating heat:
Definition
 elastic collision.
Term
 When colliding objects become tangled or coupled together.
Definition
 inelastic collision.
Term
 Impulse = __.
Definition
 Ft Units: N/s
Term
 The formula for inelastic collisions is:
Definition
 mv1+mv2=(m1+m2)Vf
Term
 The formula for elastic collisions is...
Definition
 mv1b+mv2b=mv1f+mv2f
Term
 Work is defined as _______ times ___________.
Definition
 force distance
Term
 Power = __/__
Definition
 w/t work/time
Term
 What will happen to the kinetic energy of a car if its velocity doubles?
Definition
Term
 Formula for kinetic energy.
Definition
 KE=½m(v)2
Term
 Potential energy is energy based on an objects _________ or ____________.
Definition
 location position
Term
 Kinetic energy is energy based on an object's _________.
Definition
 velocity
Term
 Machines allow a person to use less input force when performing a task because they: a. can change the direction of the force b. increase magnitude of the force c. BOTH a and b d. NEITHER a and b
Definition
 c. BOTH a and b
Term
 The amount of useful work of a certain machine is 40J. What is the efficiency of the machine if the total work input was 200J? (answer is a percent)
Definition
 20%
Term
 The amount of PE possessed by an elevated object is equal to the _____ done to _____ the object.
Definition
 work lift
Term
 Winny uses a simple lever to lift a 100N object. Winny pushes down a distance of 2m using 20 N of force. How high is the 100N object lifted off the ground?
Definition
 0.4m
Term
 All simple machines work ideally on the principle that work ______ equals ______ _______.
Definition
 input work output
Term
 Winny can lift barrels a vertical distance of 1m or can roll them up a 2m long ramp to the same elevation. If she uses the ramp, the applied force required is...
Definition
 1/2 as much.
Term
 The ratio of output force to input force of a simple machine is called the ____________ ____________.
Definition
Term
 PE =
Definition
 mgh OR Fh
Term
 Efficiency =
Definition
 AMA/TMA×100 OR worko/worki × 100
Term
 AMA =
Definition
 input distance/output distance
Term
 Power = __/__
Definition
 w/t work/time
Term
 A car traveling at 50 km/h skids 15 m. How far will the car skid if its speed doubles to 100 km/h?
Definition
 60 m.
Term
 What will happen to the kinetic energy of a car if its velocity doubles?
Definition
Term
 Potential energy is energy based on an objects _________ or ____________.
Definition
 location position
Term
 Kinetic energy is energy based on an object's _________.
Definition
 velocity
Term
 Machines allow a person to use less input force when performing a task because they: a. can change the direction of the force b. increase magnitude of the force c. BOTH a and b d. NEITHER a and b
Definition
 c. BOTH a and b
Term
 The amount of useful work of a certain machine is 40J. What is the efficiency of the machine if the total work input was 200J? (answer is a percent)
Definition
 20%
Term
 The amount of PE possessed by an elevated object is equal to the _____ done to _____ the object.
Definition
 work lift
Term
 Winny uses a simple lever to lift a 100N object. Winny pushes down a distance of 2m using 20 N of force. How high is the 100N object lifted off the ground?
Definition
 0.4m
Term
 All simple machines work ideally on the principle that work ______ equals ______ _______.
Definition
 input work output
Term
 Winny can lift barrels a vertical distance of 1m or can roll them up a 2m long ramp to the same elevation. If she uses the ramp, the applied force required is...
Definition
 1/2 as much.
Term
 The ratio of output force to input force of a simple machine is called the ____________ ____________.
Definition
Term
 PE =
Definition
 mgh OR Fh
Term
 Efficiency =
Definition
 AMA/TMA×100 OR worko/worki × 100
Term
 AMA =
Definition
 input distance/output distance
Term
 An ____ is the straight line around which rotation takes place.
Definition
 axis
Term
 What is the difference between rotation and revolution?
Definition
 Rotation is on an internal axis, but revolution is on an external axis.
Term
 _______ speed is distance moved per unit of time.
Definition
 Linear
Term
 __________ speed is the number of rotations per unit of time.
Definition
 Rotational
Term
 Speed of something moving along a circular path can be called ___________.
Definition
 tangential
Term
 Any force that causes an object to travel along a circular path is called a _______________ force.
Definition
 centripetal
Term
 Centripetal means...
Definition
 "center-seeking" OR "toward the center"
Term
 Centrifugal means...
Definition
 "center-fleeing" OR "away from the center"
Term
 The higher the center of gravity, the ______ the stability will be.
Definition
 lower
Term
 Three kinds of equilibrium:
Definition
 1. Stable equilibrium 2. Unstable equilibrium 3. Neutral equilibrium
Term
 Describe STABLE equilibrium.
Definition
 low center of gravity, work is required to raise the CG
Term
 Describe UNSTABLE equilibrium.
Definition
 higher CG, any movement lowers the CG.
Term
 Describe NEUTRAL equilibrium.
Definition
 movement neither raises nor lowers the CG.
Term
 A ball that is whirled on the end of a string moves in a circle because the _________ of the string creates an ________ force on the ball.
Definition
 tension inward
Term
 If a car is traveling in a circle at a constant speed, the net force on the car is directed _______ because the car is traveling in a circle.
Definition
 inward
Term
 Which has a greater rotation speed: a horse nearer the outside rail of a carousel or a horse near the inside rail of a carousel?
Definition
 Neither, they both have the same rotational speed.
Term
 Which has a greater tangential/linear speed: a horse nearer the outside rail of a carousel or a horse near the inside rail of a carousel?
Definition
 The outside horse
Term
 An object wants its COG to be ______.
Definition
 lower
Term
 What is the centripetal force of a 2 kg tether ball that is connected to a 3 m long piece of rope and is hit with a velocity of 3 m/s?
Definition
 6 N
Term
 Which object will experience the greatest acceleration down an inclined plane? a. object with large rotational inertia b. object with small rotation inertia c. Neither because acceleration is dependent of rotational inertia.
Definition
 b. an object with a small rotational inertia
Term
 Torque is defined as _____ perpendicular times _______.
Definition
 force distance
Term
 Force causes acceleration; torque causes __________.
Definition
 rotation
Term
 Which object will experience the greatest acceleration down an inclined plane? a. and object with a large rotational inertia b. an object with a small rotational inertia c. NEITHER because acceleration is independent of rotational inertia
Definition
 b. an object with a small rotational inertia
Term
 Angular momentum is defined as...
Definition
 rotational inertia time rotational velocity
Term
 An object will maintain its angular momentum unless acted upon by an unbalanced...
Definition
 torque.
Term
 Why did Newton think there was a force acting on the moon?
Definition
 Because the moon moves in a curved path instead of a straight line.
Term
 Newton reasoned that the gravitational attraction between Earth and the moon must be ____________ or ___________ by distance.
Definition
 reduced or weakened
Term
 Since Earth is attracted to the sun, why doesn't it fall into the sun?
Definition
 Because it has sufficient tangential velocity.
Term
 If the mass of the earth increased, with no change in the radial distance, your weight would...
Definition
 increase also.
Term
 If the radius of earth decreased, with no change in mass, your weight would _________.
Definition
 increase
Term
 The moon and earth move toward each other under mutual gravitation: which has the greater force?
Definition
 They are the SAME!
Term
 Suppose the gravitational force between two massive spheres is 100 N. If the distance between the spheres is doubled, what is the force between the masses?
Definition
 25 N.
Term
 By noticing the perturbations of known planets, astronomers using the law of gravitation were able to discover the __________ of other planets and _____, such as Pluto and Uranus' ______.
Definition
 presence moons moons
Term
 Equation for Torque.
Definition
 T= Fperpendicular × d
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