127 terms

# Physical Science 9-weeks Study Guide

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A testable prediction is a(n)
hypothesis
When designing an experiment, the first step is to
state the problem
A standard for comparison that helps to ensure that the experimental result is caused by the condition being tested is the
control
A factor that changes in an experiment from manipulation of the independent variable is the
dependent variable
A factor that does not change in an experiment is the
constant
An organized process used to gather observations and test a hypothesis is a(n)
experiment
A statement that describes what happens in nature is a
scientific law
An explanation of an event that is based on repeated observations and experiments is a
theory
An idea, event, or object that can be used to represent something you are trying to explain is a
model
The lightbulb is an example of
technology
In an experiment to determine if the popping or popcorn is affected by the temperature at which it is stored, counting the popped kernels is an example or a(n)
observation
A measurement standard is defined as
an exact quantity people agree to use for comparison
The correct symbol for the SI unit of temperature is
K
In a graph, the variable on the horizontal axis is the
independent variable
The type of graph that would be used to show how some fixed quantity is broken down into parts is a
circle graph
In a graph showing how the temperature of a material changes over time, temperature change is the
dependent variable
A unit of measurement that is obtained by combining other units is a __ unit
derived
Of the following, the most correct way to express density is
g/cm^3
Of the following, the only unit that cannot be used to express volume is
kg
If you ride your bike down a straight road for 500m then turn around and ride back, your distance is __ your displacement.
greater than
Motion is a change in
position
The speed you read on a speedometer is
instantaneous speed
3m/s north is an example of a(n)
velocity
The relationship among speed, distance, and time is
s= d/t
A single point on a distance-time graph tells that
instantaneous speed
A merry-go-round horse moves at a constant speed but at a changing
velocity
Acceleration is rate of change of
velocity
If you ride your bike up a hill, then ride down the other side, your acceleration is
first negative, then positive
The equation used to find acceleration is a
vf-vi/t
Inertia varies depending on
force
Newton's first law of motion is also called law of
inertia
Examine figure 11-1. If you were standing under the tree, which object would appear to be moving?
the airplane
a passenger in the rear seat of a car moving at a steady speed is at rest relative to
the front seat of the car
Which distance can be most accurately measured with a ruler?
the width of a book
On kilometer equals 1000 meters. What does the prefix kilo- means?
1000
What is the most appropriate SI unit to express the speed of a cyclist in the last leg of a 10-km race?
km/h
Speed is the ratio of the distance an object moves to
the amount of time needed to travel the distance
Instantaneous speed is measured
at a particular instant
A horizontal line on a distance-time graph means the object is
at rest
The rate at which velocity changes is called
acceleration
Which example describes constant acceleration due ONLY to a change in direction?
traveling around a circular track
An object that is accelerating may be
all of the above (slowing down, gaining speed, changing direction)
What is instantaneous acceleration?
how fast a velocity is changing at a specific instant
Which of the following statements is true?
An object at rest has an instantaneous acceleration of zero.
The upward force on an object falling through the air is
air resistance
The relationship among mass, force , and acceleration is explained by
Newton's second law of motion
A feather will fall through the air more slowly than a brick because of
Air resistance
In the absence of air, a penny and a feather that are dropped from the same height at the same time will
fall at the same reate
The acceleration due to gravity is
9.8 m/s^2
According to Newton's second law of motion
F=ma
When an object moves in a circular path, it accelerates toward the center of the circle as a result of
centripetal force
The path of a projectile is
curved
For any object, the greater the force that's applied to it, the greater its ___ will be.
acceleration
The size of the gravitational force between two objects depends on their
masses and the distance between them
When a force is exerted on a box, an equal and opposite force is exerted by the box. These forces are called __ forces.
action-reaction
A real care moving at 10 km/h has more momentum than a toy car moving at the same speed because the real car
has greater mass
In the equation p=mv, the p represents
momentum
The statement "to every action there is an equal and opposite reaction" is
Newton's third law of motion
The unit of momentum is
kgxm/s
When two balls collide, the momentum of the balls after the collision is explained by
the law of conservation of momentum
An object that is in free fall seems to be
weightless
If gravity did NOT affect the path of a horizontally thrown ball, the ball would
fall straight
The SI unit of force is the
newton
Which of the following relationships is correct?
1N = 1 kgm/s^2
When an unbalanced force acts on an object
the object accelerates
When a pair of balanced forces acts on an object, the net force that results is
equal to zero
What kind of frictions occurs as a fish swims through water?
fluid
As you push a cereal box across a tabletop, the sliding friction acting on the cereal box
acts in the direction opposite of motion
The forces acting on a falling leaf are
gravity and air resistance
An open parachute increases air resistance of a falling sky diver by
increasing surface area
Projectile motion is caused by
the downward force of gravity and an initial forward velocity.
The property of matter that resists changes in motion is called
inertia
An orange might roll off your cafeteria tray when you stop suddenly because of
the orange's inertia
According to Newton's second law of motion, the acceleration of an object equals the net force actin on the object divided by the object's
mass
mass times the acceleration due to gravity
The acceleration due to gravity on the surface of Mars is about one third the acceleration due to gravity on Earth's surface. The weight of a space probe on the surface of Mars is about
one third its weight on Earth's surface.
Newton's third law of motion describes
action and reaction forces
In which of the following are action and reaction forces involved?
all of the above
The product of an object's moss and velocity is its
momentum
What force is responsible for the repulsion between two positively-charged particles
electric
When opposite poles of two magnets are brought together, the poles
attract each other
Which universal force acts only on the protons and neutrons in a nucleus
strong nuclear
With which of the following is the weak nuclear force associated?
nuclear decay
Which of the following universal forces is the weakest?
gravitational
As an astronaut travels far away from Earth, her weight
decreases because gravity decreases
The gravitational force between two objects increases as mass
increases or distance decreases.
The force that keeps an object in a circle is called
centripetal force
Which of the following is not used to calculate kinetic energy?
height
Which of the following is not used to calculate potential energy?
speed
Thermal energy is measured in
joules
The __ energy of an object increases with its height.
potential
The kinetic energy of an object increases as its __ increases.
speed
Mechanical energy is the total kinetic and __ energies in a system.
potential
__ can cause kinetic energy to change into thermal energy.
friction
Green plants convert light energy from the sun into
chemical potential energy
The mechanical energy of a coconut falling from a tree
remains constant
The law of __ states that energy in a system can change forms but can never be created or destroyed.
conservation of energy
The kinetic energy of an object increases as its __ increases
velocity
Increasing the speed of an object __ its potential energy.
does not affect
The SI unit for energy is the
joule
You can calculate kinetic energy by using the equation
KE=1/2m x v^2
You can calculate gravitational potential energy by using the equation
GPE = m x 9.8
Which of the following devices does not make use of electrical energy?
upright piano
A bus engine transfers chemical potential energy into __ so that the bus moves
kinetic energy
In a nuclear fusion reaction, mass is transformed into
energy
According to the law of conservation of energy, the total amount of energy in the universe
remains constant
Work is a transfer of
energy
What is transferred by a force moving an object through a distance?
energy
The energy of motion is called
kinetic energy
An object's gravitational potential energy is not directly related to which of the following?
its speed
Which of the following is an example of an object with elastic potential energy?
all of the above
Why is the gravitational potential energy of an object 1 meter above the moon's surface less than its potenial energy 1 meter above Earth's surface?
the object's acceleration due to gravity is less on the moon
The gravitational potential energy of an object is always measured relative to the
reference level from which the height is measured.
Which of the following increases when an object becomes warmer?
thermal energy
The energy stored in gasoline is
chemical energy
The total potential an d kinetic energy of all the microscopic particles in an object make up its
thermal energy
Walking converts what type of energy into mechanical energy?
chemical
Nuclear power plants are designed to convert nuclear energy into what type of energy?
electrical
Solar cells convert what type of energy into electrical energy?
electromagnetic
Which of the following statements is true according to the law of conservation of energy.?
all of the above
If no friction acts on a diver during a dive, then which of the following statements is true?
KE + PE = KE + PE
the mechanical energy of an object equals its
kinetic energy plus its potential energy
The equation e=mc^2 relates energy and
mass
In which of the following does Einstein's famous equation apply?
nuclear fission and fusion reactions
Which of hte following statements is a consequence of the equation e=mc^2
all of the above
A drawback of solar energy is that it
depends on the climate
A benefit of a hydrogen fuel cell is that its byproduct is
water