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61 Cards in this Set
 Front
 Back
How does velocity differ from speed?

VelocityVector
(includes direction) SpeedScalar 

How does average velocity differ from istantaneous velocity?

average is taken over period of time; instantaneous is one given moment


What is acceleration?

rate at which velocity changes


Can you accelerate at a constant speed?

yes, while turning


What does it mean to be in free fall?

only force on you is gravity


What is the acceleration of an object in free fall?

9.8 m/s(squared)


What is the initial velocity of a dropped object?

0


When is the equation d=vt used? When is d=(1/2)at(squared) used?

d=vtwhen speed is constant
d=(1/2)at(squared)speed is changing, when initial velocity is zero 

What is the difference between a vector and scalar?

vectormeasurement w/ direction
scalarmeasurement w/o direction 

Why doesn't gravity slow a ball down that's rolling on the ground?

gravity is a vertical force, does not affect horizontal motion


Does gravity affect the hoizontal motion of a projectile?

No


If you drop a bullet and fire a bullet from a horizontal rifle simutaneously, which bullet will hit the ground first? Why?

same time, b/c same initial vertical velocity


What is Newton's first law? (inertia)

an object at rest will stay at rest, an object in motion will stay in motion unless acted upon by an outside force


How does intertia relate to seatbelts? Headrests?

seatbeltsobject in motion will stay in motion(deccelerating)
headrestsobject at rest will stay at rest(accelerating) 

What are mass and weight? Describe units, vector/sclar, and key differences.

Massscalar, kg, measure of an object's inertia or matter in an object
Weightvector, N, gravitational pull on an object 

Why do scientists prefer mass to weight?

mass is universal


What is equilibrium? What is the net force?

when net force is 0 N


Is an object at a constant velocity in equilibrium?

Yes


What is the upward force that keeps a book on a table in equilibrium?

normal/support force


What is Newton's second law?

net force on an object causes acceleration that is proportional to force and inversely proportional to the mass; same direction as net force


What is the relationship between force and acceleration?

directly proportional


What is the relationship between mass and acceleration?

inversely proportional


What is friction?

resistive force of two objects' grip


What is the relationship between force and pressure?

directly proportional


What is the relationship between area and pressure?

inversely proportional


Summarize Newton's third law.

every force causes an equal and opposite reaction force


What is momentum?

measure of an object's forward progress
p=mv 

What is the momentum of an object at rest?

0


Is momentum conserved?

Yes


What type of collision causes two objects to hook together?

completely inelastic


What is work? Give the units.

changing an object's energy, joules


Can someone do work on an object at rest?

No


What is the relationship between power and time?

inversely proportional


What are the two types of mechanical energy?

kinetic and potential


What is kinetic energy?

energy of motion


When an object doubles its speed, what happens to the kinetic energy?

quadrupoles


Is energy conserved?

Yes


How is energy lost?

heat because of friction and air resistance


What is the difference between rotational and tangential speed?

rotationalrotations/time
tangentialdistance/time 

What is centripetal?

inward


What happens if CG extends over support base?

object topples


What does universal gravity mean?

all objects in the universe exert forces on each other


Why doesn't the earth crash into the sun due to gravity?

great tangential speed


Why was Cavendish's discovery important?

enabled the discovery of the mass of the earth


Why do objects in orbit float?

in free fall


What is an atom?

substance w/ same # of protons


What are the four phases of matter?

plasma, gas, liquid, solid


What is the SI unit of charge?

coulomb (C)


What is coulomb's law?

F=[kq(1)q(2)]/d(squared)


Give an example of a solid w/ a crystal structure?

ice, salt, sugar, etc...


Give an example of an amorphous solid?

glass


What is the relationship between volume and density?

inversely proportional


Does liquid pressure push down on an object only from above?

no, all sides


How can a dam holding back a small pond be under more pressure than a dam holding back Lake Superior?

if it is deeper


Is upward pressure on the bottom of an object the same as downward pressure on the to?

no, upward pressure is greater because pressure increases w/ depth


What is buyant frce?

upward force on immersed obct


What is the buoyant force equal to? What principle is this?

weight of fluid displaced; Archimedes'


Does buoyant force increase with depth?

no


Can you change a liquid's volume or density?

no, it cannot be compressed like a gas


What is Boyle's law?

pressure and volume of a gas are inversely proportional
P(i)V(i)=P(f)V(f) 

What is Bernouilli's Priciple?

as speed of fluid increases, pressure decreases
