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96 Cards in this Set
 Front
 Back
The motion of an object looks differnernt to observers in different...

frames of reference


The direction and length of a straight line from the starting point to the ending point of an object's motion is...

displacement


the SI unit for measuring _______ is meter.

distance


Displacement and velocity and examples of ________ because they have both magnitude and direction.

vectors


The sum of two or more vectors is called the...

resultant vectors.


Speed is measured in units of...

meters per second.


A car's speedometer measures...

instant speed.


v=D/t is the equation that defines...

average speed.


A constant slope on a distanetime graph indicates ________ speed.

constant


The difference between speed and velocity is that velocity indicates the ________ of motion and speed doesn't

speed


A distancetime graph indicates an object moves 20 km in 2 h. The average speed of the object is ______ km/h

10


Because its __________ is always changing, an object moving in a circular path experiences a constant change in velocity.

direction


Two or more velocities add by _________________

vector addition


A moving object does not ________ if its velocity remains constant

acceleration


Freely falling objects accelerate at 9.6 m/s squared because the force of_____________ acts on them

gravity


The velocity of an object moving in a striaght line changes at a constant rate when the object is expierencing constant___________

acceleration


The acceleration of a moving object is calculated by diiding the change in _______ by the time which change occurs

speed or velocity


Accelerated motion is represtented by a(an) ________ line on a distancetime graph

curved


A car that incrases its speed from 20 km/h to 100 km/h undergoes _________ acceleration

postive


___________ is how fast a velocity is changing at a specific time

instantaneous speed


A push or pull is an example of a(an)_________

force


The type of force measured by a grocery store spring scale is__________

weight


The sum of all the forced acting on an object is called the ____________

netforce


If the forced acting on an object produce a net force of zero, the forces are called __________

balenced forces


The force that oppeses the motion of objects that touch as they move pass each other is called ___________

friction


It usally takes more force to start an object sliding than it does to keep an object sliding because static frictin is usally ________ than sliding friction

greater


The two forces acting on a falling object are gravity and ________

air resistance


The path of motion of a thrown javelin is a example of

projectile


The tendency of an object to resist any change in its motion is called

inertia


During a head on auto collision____________ causes a passenger in the front seat to countinue moving _________

inertia, forword


The acceleration of an object is equal to the net _____ acting on the object divided by the objects ________

force, mass


The force of gravity acting on an object is the object's...

weight


If a golf ball and bowling ball are rolling at the same speed, the _______ ball has greater momentum

bowling


When you push on a wall, the ________ pushes back on you.

wall


In a closed system, the loss of momentum of one object ________ the gain in momentum of another object

equals


The observation that a charged object can attract or repel other charged objects led scientists to conclude that there are ____ types of charges

two


The universal force that is the most effective over the longest distances is...

gravity


The centripal force acting on the moon continuously changes the ___________ of the mooon's motion.

direction


Pressure is the result of force distributed over an...

area


The formula, Force/Area, is used to calculate...

pressure


The SI unit of pressure is the...

pascal


A pascal, the SI unit of pressure, is equal to 1 newton per...

square meter


A substance that flows and assumes the shape of its container is a...

fluid


As a liquid is added to a beacker, the pressure exerted by the liquid on the bottom of the beacker...

increases


The pressure exerted by a fluid at any given depth is exerted _________ in all directions.

equally


As your altitude increases, air pressure...

decreases


A hydraulic jack is an application of _______ principle

Pascal's


A device that uses pressurized fluids acting on pistons of defferent sizes to change a force is called a...

hydrolic system


As the speed of a fluid increases, the _______ within the fluid decreases

pressure


In a hydrolic lift system, the fluid pressure exerted throughout the system is

constant


The downward force produced when air flows over the winglike spoiler on a race car is an example of _____________ principle

Bournouli's


The apparent loss of weight of an object in a fluid is called ________

bouancy


The direction of the buoyant force on an object placed in a fluid is

upward


Even a rock at the bottom of a lake has a ____________ force acting upward.

bouyant


The unit g/cm3 is often used to express _______

density


As you climb a high mountain, the buoyant force exerted on you by the atmosphere _________

decreases


A submerged submarine alters its __________ to rise or fall in the water.

density


The weight of an object that sinks in a fluid is _________ greater than the buoyant force acting on it.

greater


For work to be done on an object, the object has to __________

move


Any part of a force that does not act in the direction of an object's motion does no ________ on an object.

work


The SI unit of work is

joules


You calculate work by multiplying the force acting in the direction of _______ by the distance the object moves.

motion


The rate at which work is done is called

power


The SI unit of power is

watt


The watt and the horsepower are both units of

power


A machine is a device that changes a

force


A device that changes the size or direction of force used to do work is called a

machine


The force that is exerted on a machine is called the ________ force

input


Besides a reduction in friction, the only way to increase the amount of work output of a machine is to ________ the work input

increase


The ________________ of a machine is the number of times that the machine increases the input force.

mechanical advantage


The mechanical efficiency of any machine is always _______ than 100 percent

less


A _________ can be described as an inclined plane wrapped around a cylinder

screw


The fulcrum is always between the effort force and the resistance force in a ________class lever

first


The ideal mechanical advantage of a thirdclass lever is always ________ than 1

less


As the thickness of a wedge of given length increses, its IMA

decreases


Two or more simple machines working together make up a __________ machine

compound


A watch consists of a complex systems of gears. Each gear acts as a continuous

lever


Energy of an object increses when ____________ is done on the object

work


Energy and work are measured in the SI unitcalled the

joule


If the ________ of an object doubles, its kinetic energy doubles

mass


The kinetic energy of an object is propotional to the sqare of its

speed


Energy that is stored due to position or shape is called _________ energy

potential


When a polevaulter flexes the pole, the polevaulter increases the pole's __________ potential energy

elastic


You can calculate an object's gravitational potential energy by using the equation

potential energy = mass x acceleration of gravity x height


Mechanical energy does not include kinetic energy of ______ energy

chemical


The sum of the kinetic energy and potential energy of an object is called its _______ energy

mechanical


All energy can be considered as kinetic energy, _________ energy or the energy in fields.

potential


Wind turbines comvert ________ energy into electrical energy

kinetic


the process of changing energy from one form to another is called energy _____________

conversion


"Energy cannot be created or destroyed" is a statement from the law of

conservation of energy and mass


When an apple falls from a tree to the ground, the apple's beginning kinetic energy and ending gravitational potential energy are both equal to

0(zero) joules


In the equation E = mc2, c is the speed of

light


Energy resources that exist in limited amounts and, onece used, cannot be replaced except over the course of millions of years are called ___________ energy resources

nonrenewable


Flat collector plates through which water flows are found in ___________ solar energy systems

active


Geothermal energy, in addition to being renewable, offers the benefit of being

nonpolluting


Turning off unused lights or appliances is an example of energy

conservation
