The Empirical World Lecture - TEST 1
A tow truck exerts a force of 3000 N on a car, accelerating it at 2 m/s2. What is the mass of the car?
1500 kg
A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is
300 N upward
A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is actually
3000 N
speed of sound
340 m/s in air @ 20 degrees celcius
A car accelerates from rest at 2 m/s2. What is its speed 3 s after the car starts moving?
6 m/s
A wave travels an average distance of 6 m in 1 s. What is the wave's velocity?
6 m/s
The weight of 0.6 kg of salami is about...
6.0 N
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface?
6N
The two measurements necessary for calculating average speed are...
distance and time
Speed EQ
distance over time Distance covered/travel time
Whereas Aristotle relied on logic in explaining nature, Galileo relied on...
experiment
The scientific spirit is based upon...
experimentation.
Energy transfer by convection is primarily restricted to
fluids
Fahrenheit Scale
freezing water: 32 boiling point: 212
Kelvin Scale
freezing: 273 boiling: 373
High-pitched sound has a high...
frequency
When you touch a cold piece of ice with your finger, energy flows...
from your finger to the ice
When a scientist is dishonest and reports false information, he or she...
gets no second chance in the scientific community.
A good absorber of radiation is a...
good emitter of radiation
The reason the Sun's radiant energy is of shorter wavelengths than the Earth's is because the Sun
has a higher temperature than the Earth.
An object following a straight-line path at constant speed...
has zero acceleration
2nd law of thermodynamics
heat never spontaneously flows from a lower temperature subject to a higher temp subject
Which of the following expands most when the temperature is increased? Equal volumes of...
helium
Equilibrium Rule
if the sum of all forces is zero, object does not move. An object that moves at a constant velocity is in equilibrium
temperature and sound
increase in temp- increase in sound
As a system becomes more disordered, entropy...
increases
If an object's mass is decreasing while a constant force is applied to the object, the acceleration...
increases
We are NOT best at hearing...
infrasonic or ultrasonic sound
Most natural phenomena we wonder about...
involve several scientific disciplines.
convection
involves movement of warmer substances to cooler ones; occurs in liquids and gases
light travel v. sound
light travels a million times faster than sound
Waves diffract the most when their wavelength is...
long
sound travel in what waves?
longitudinal
A sound wave is a...
longitudinal wave
A substance that heats up relatively quickly has a...
low specific heat capacity
A kilogram is a measure of an object's...
mass
Density equation
mass over volume (DMV)
Density is the ratio of...
mass to volume
In science, facts...
may change.
Density
measure of how much mass occupies a given space
Atoms and molecules are always...
moving
Acceleration of force eq
net force over mass
3rd law of thermodymanics
no system can reach absolute zero
conduction
occurs in solids
interference
overlapping waves
A good heat conductor is a...
poor insulator
The Moon is made of green cheese. This statement is a...
scientific hypothesis.
Two identical blocks of iron, one at 10°C and the other at 20°C, are put in contact. Suppose the cooler block cools to 5°C and the warmer block warms to 25°C. This would violate the
second law of thermodynamics
The statement, "There are regions beneath Earth's crust that will always be beyond the reach of scientific investigation," is a...
speculation.
Sound travels faster in...
steel
Ice tends to form at the...
surface of bodies of water
constructive inerference
the crest of one wave overlaps the crest of another wave. The individual effects add, resulting in a wave of increased amplitude. (bigger wave)
destructive interference
the crest of one wave overlaps the trough of another. Individual effects are reduced. (no wave)
Your weight is...
the gravitational attraction between you and the Earth.
A feather and a coin will have equal accelerations when falling in a vacuum because...
the ratio of each object's weight to its mass is the same.
If experimental findings are not reproducible,
the results are not considered valid
Compared with the mass of a certain object on Earth, the mass of the same object on the Moon is...
the same
refraction
bending of waves due to change of medium or speed of wave
What color light is transmitted by a piece of blue glass?
blue
Is light a wave or particle?
both
Doppler Effect
change in frequency as measured by an observer due to the motion of the source or listener
acceleration eq
change of velocity over time interval
Consider a sample of water at 0°C. If the temperature is slightly increased, the volume of water
contracts
The mass of a pet turtle that weighs 10 N is about...
1 kg
10 Newtons is
1 kilogram
In science, an educated guess is..
a hypothesis.
In science, a theory is...
a synthesis of a large body of well-tested knowledge.
Sound waves cannot travel in
a vacuum
A falling object that has reached its terminal speed does not gain...
acceleration or speed
Science, art, and religion do not contradict one another because...
all three have different domains.
acceleration of a NON free-fall object is
always less than g!
The vector quantity is represented by...
an arrow
free fall
10 m/s per second (squared) when acceleration is "g"
The lowest temperature possible in nature is...
-273 degrees C
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
0 N
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is...
0 N
If the frequency of a certain wave is 10 Hz, its period is
0.1 s
Celsius Scale
Freezing water: 0 Boiling water: 100
The scientist to first introduce the concept of inertia was...
Galileo
A force is a vector quantity because it has both...
Magnitude and direction
The color _____ has the lowest frequency and the color _____ has the highest frequency of the light spectrum.
Red, Violet
When a squid pushes against water, the squid moves forward because
the water pushes against the squid
radiation
thermal energy transferred by electromagnetic waves
specific heat capacity
thermal inertia that indicates resistance of a subject to a change in temp
Average speed eq
total distance over travel time
what waves does light/electromagnetic waves travel in?
transverse waves
all substances above zero emit radiant energy
true
Which direction does a table push a book resting on it?
up
Light travels faster in a...
vacuum
The source of all wave motion is a...
vibrating object
transverse wave
vibration @ right angles (sideways) to wave travel (vibrations perpendicular to wave)
longitudinal wave
vibration in direction of travel (same direction along the wave)
During a very cold winter, water pipes sometimes burst. The reason for this is...
water expands when freezing
equation for wave speed
wave speed= frequency x wavelength
1st law of thermodynamics
when heat flows in/out of a system, the gain/loss of thermal energy = amount of heat transferred
A scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test for proving it...
wrong
The complementary color of blue is...
yellow
The brightest color emitted by the Sun is...
yellow-green