Final Exam. Flashcards by Olivia Simoneaux

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.

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Which one of the following is a scientific statement?
A. There are things we will never know about.
B. The moon is made of green cheese.
C. Matter is filed with undetectable particles
D. There are parts of the universe that will never be found by man.

B. The moon is made of green cheese.

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When a rocket ship accelerating in outer space runs out of fuel it..

accelerates for a short time, and then slows down to a constant velocity.

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Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to..

follow a straight line path.

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An object in mechanical equilibrium can be an object...
A. at rest
B. having no acceleration
C. moving with constant veocity
D. all of these.

D. all of these

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What is the weight of a 200-kg bear?

2000 N

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A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor…

exactly below the midpoint of the ceiling.

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Which one of the following descriptions violates Newton’s first law of motion?
A. a glass of water is sitting on a table in the dining car of a train. The train brakes as it nears the station, and the glass slides forward.
B. A child is sitting in the back seat of a car and is not wearing a seat belt. The car is traveling forward and the driver suddenly applies the brakes. The child flies forward against the rear side of the front seat.
C. A small suitcase is at the front of the overhead luggage compartment on an airplane. When the airplane begins its takeoff, the suitcase slides to the rear of the compartment.
D. A rabbit’s foot is hanging on a chain from the rearview mirror of a car. As the car accelerates forward, the rabbits foot swings toward the windshield.

D. A rabbit’s foot is hanging on a chain from the rearview mirror of a car. As the car accelerates forward, the rabbits foot swings toward the windshield.

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A horse gallops a distance of 20 kilometers in a time of 30 minutes. It’s average speed is…

40 km/h

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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 a constant velocity is…

zero.

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Twelve seconds after starting from rest, an object falling freely on Earth will have a speed of…

more than 100 m/s

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A bal is thrown upwards and returns to the same position. Compared with it’s original speed after release, its speed when it returns is about…

twice as much.

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Someone standing at the edge of a cliff throws one ball straight up and another ball straight down at the sam initial speed. Neglecting air resistance, the ball to hit the ground below the cliff with the greater speed will be…
A. the one thrown upwards
B. the one thrown downwards.
C. neither, they will both hit with the same speed.

C. neither, they will both hit with the same speed.

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Your weight is..

the gravitational attraction force between you and the Earth.

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If one object has twice the mass of another object, it also has twice as much..

inertia.

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Strange as it may seem, it is just as hard to accelerate a car on a level surface on the moon as it is here on Earth. This is because…

The mass of the car is independent of gravity.

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When a falling object has reached it’s terminal velocity, it’s acceleration is…

zero.

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An object is propelled along a straight-line path in space by force. If the mass of the object somehow becomes twice as much with force remain unchanged, its acceleration…

halves.

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Which has zero acceleration? An object...
A. at rest
B. In mechanical equilibrium.
C. Moving at constant velocity
D. all of these

D. all of these.

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An object is pulled northward by a force of 15 N and at the same time another force of 25 N pulls it southward. The magnitude of the resultant force on the object is..

10 N

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For an action force, there must be a reaction force that…

is exactly equal in magnitude.

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A player catches a ball. Consider the action force to be the impact of the ball against the player’s glove. The reaction to this force is the…

Force the glove exerts on the ball.

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A Mack truc and a volkswagon traveling at the same speed have a head-on collision. The vehicle that undergoes the greatest change in velocity will be the…

volkswagon.

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The attraction of a person’s body toward Earth is called weight. The reaction to this force is…

the person’s body pulling the Earth.

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Which one of the following is true, according to Newton's laws of motion (remember all three laws)? Ignore friction. A. A semitrailer truck crashes all the way through a wall. Since the wall collapses, the wall sustains a greater force than the truck does. B. Two astronauts on a space walk are throwing a ball back and forth between each other. In this game of catch the distance between them remains constant. C. Sam (18 years old and larger) and his sister (9 years old) go ice skating. The push off against each other and fly apart. Sam flies off with the greater acceleration. D. A sports utility vehicle (SUV) hits a stationary motorcycle. Since it is stationary, the motorcycle sustains a greater force than the SUV does. E. None of these are true, according to the third law.

E. None of these are true, according to the third law.

It is correct to say that impulse is equal to...

the change in momentum it produces.

Suppose that a tiny gun made of strong but very light material fires a bullet that is more massive than the gun itself. For such a weapon...

the target would be safer than the shooter because the weapon's recoil would be dangerous.

To catch a ball, a baseball player extends the hand forward before impact with the ball and then lets it ride backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because the...

Time of impact is increased.

``` A car traveling along the highway needs a certain amount of force exerted on it to stop it in a certain distance. More stopping force is required when the car has... A. more mass B. more momentum C. less stopping distance. D. all of these ```

D. all of these

Two billiard balls having the same mass and speed roll towards each other. What is their combined momentum after they meet?

zero

Two train cars both with a mass of 1000 kg are on a track. The one train car is at rest while the other is moving towards it at 6 m/s. The two cars collide and couple together. What is the final speed of the coupled train cars after the collision?

3 m/s

If you push an object twice as far while applying the same force, you do

twice as much work.

If you do work on an object in one-thirde the usual time, your power output is...

three times the usual power output.

Say that an object is lifted 5 meters gains 400 J of potential energy. If the same object is lifted 10 meters, its potential gain is..

twice as much.

An object that has kinetic energy must be...

moving

When an automobile is braked to a stop, its kinetic energy is transformed to...

heat

Compared to the recoiling rifle, the bullet fired has...

a greater kinetic energy.

Which moves faster in m/s on a merry-go-round: a horse on the inside or a horse on the outside near the outer rail?

outside horse.

A broom is easier to balance on it's end when the heavier end (the brush end) is...

highest, farthest from your hand.

Torque acting on an object tends to produce...

rotation.

The chef at the infamous fattening tower of pizza tosses a spinning disk of uncooked pizza dough into the air. The disk's diameter increases during the flight, while its rotational speed...

decreases.

according to newton, doubling the distance between two interacting objects...

divides by 4 the gravitational force between them.

An asteroid exerts a 360 N gravitational force on a nearby spacecraft. This force is directed...

towards the asteroid.

If the radius of the Earth somehow decreased with no change in mass, your weight would (hint: think how the earth's gravity would change with a shorter separation distance)

increase.

When the distance between two stars decreases by half, the force between them...

increases to four times as much.

Roll a bowling ball off the edge of the table. As it falls, its horizontal component of velocity...

remains constant.

A projectile is launched vertically upward at 50 m/s. If air resistance is negligible, its speed upon returning to its starting point is...

50 m/s.

A projectile is fired horizonally in a region of no air resistance. The projectile maintains its horizontal component of velocity because..

it is not acted on by any horizontal forces.

A bullet fired horizontally over level ground hits the ground in 0.5 seconds. If it had been fired with twice the speed in the same direction, it would have hit the ground in...

Exactly 0.5s.

``` Which of the following are electrically neutral? A. proton B. electron C. ion D. neutron ```

D. neutron

``` Which of these atoms has the most mass? A. Uranium B. Lead C. Iron D. Hyrdrogen ```

A. Uranium

In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of...

orbital electrons.

The chemical properties of matter come mostly from its...

electrons.

If one neutron is added to a helium nucleus, the result is an isotope of...

helium.

When a chocolate bar is cute in half, its density is...

unchanged.

if a loaf of bread is compressed, its...

density increases.

If the mass of an object were to double while its volume remains the same, its density would...

double.

A wooden block has a mass of 1000 kg and a volume of 2 cubic meters. What is the block's density?

500 kg per cubic meter.

A strong spring is stretched 10 cm by a suspended weight. If the weight is doubled, the spring will stretch...

another 10cm, making the total stretch 20 cm.

A metal block has a density of 5000kg per cubic meter and a mass of 15,000 kg. What is its volume?

3 cubic meters.

A dam is thicker at the bottom than at the top partly because...

water pressure is greater with increasing depth.

What is the buoyant force acting on a 10-ton ship floating in the ocean?

10 tons.

When an object is partly or wholly immersed in a liquid, it is buoyed up...

by a force equal to the weight of the liquid displaced.

The reason of a life jacket helps you float is...

the density of both you and the jacket together is less than your density alone.

The density of a submerged submarine that is neither sinking nor floating to the surface, but remaining at the same depth, is about the same as the density of..

water.

Atmospheric pressure is caused by the...

weight of the atmosphere.

A balloon is buoyed up with a force equal to the...

weight of air it displaces.

A bubble of air released from the bottom of the lake...

becomes larger as it rises.

In drinking soda or water through a straw, we make use of..

atmospheric pressure.

Airplane flight best illustrates...

Bernulli's principle

An umbrella tends to move upwards on a windy day principally because... A. air pressure is reduced over the curved top surfaces. B. air gets trapped under the umbrella, warms and rises. C. buoyancy increases with increasing wind speed. D. all of these.

D. all of these.

The main difference between gases and plasmas has to do with..

electrical conduction.

heat energy travels from an object with high...

temperature to an object with a lower temperature.

A substance that heats up relatively quickly has a...

low specific heat.

When an iron bar is heated, it becomes...

larger

During a very cold winter, water pipes sometimes burst. The reason for this is...

water expands when freezing.

Aluminum has a specific heat capacity more than twice that of copper. Place equal masses of aluminum and copper wire in a flame and the one to undergo the greater increase in temerature will be...

copper.

A temperature difference of 10 degrees Celsius is also equal to a temperature difference of 10 on the...

Kelvin scale.

``` Substances absorb heat energy by the process of... A. radiation B. convection C. conduction D. all of these. ```

D. all of these.

Metals are both good heat conductors and good electrical conductors because of the..

looseness of outer electrons in metal atoms.

You feet feel warmer on a rug than a tile floor because a rug...

is a better insulator than tile so your feet don't lose as much heat.

Energy transfer by convection is primarily restricted to..

fluids, i.e. both gases and liquids.

An object will normally be a net radiator of energy when its temperature is...

higher than its surroundings.

Both black and white road surfaces absorb sunlight. At the end of a sunny day the warmer road surface will be...

the black surface.

We are warmed by condensation because water molecules in the air that strike our bodies...

transfer some of their kinetic energy to us.

When a gas is changed to a liquid state, the gas...

releases energy.

Melting snow...

cooling the surrounding air.

Ice is put into a cooler to cool the contents. To speed up the cooling process, the ice can be...

covered with salt.

A factor that usually determines whether a substance is in the solid, liquid gaseous or plasma state is its...

temperature.

The lowest temperature possible in nature is...

-273 degrees C

The first law of thermodynamics is a restatement of the...

conservation of energy.

A quantity of water has more entrophy when it is...

boiling.

One hundred joules of heat is added to a system that performs 60 joules of work. The internal energy change of the system is...

40 J

An adiabatic process is characterized by the absence of...

heat exchange.

Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees and the warmer block warms to 25 degrees C. This would violate the...

2nd Law of thermodynamics.

The source of every sound is something that is...

vibrating.

The approximate range of human hearing is...

20 hertz to 20,000 hertz.

A sound wave is a...

longitudinal wave.

Sound travels faster in...

steel.

T or F: Sound waves can interfere with one another so that no sound results.

True.

Caruso is said to have made a crystal chandelier shatter with his voice. This demonstration of...

resonance.

To say that electric charge is conserved is to say that electrical charge..

can be neither created nor destroyed.

The electrical force between charges depends only on the charges'...

magnitude and separation distance.

Two protons attract each other gravitationally and repel each other electrically. By far the greater

The electrical repulsion.

Two charges particles held close to each other are released. As they move, the force on each particles increases. Therefore the particles must have...

the same size.

Superconductors are noted for their...

absence of electric resistance.

A difference between electric forces and gravitational forces is that gravitational forces are not affected by...

repulsive interaction.

Charge carriers (what allows current to flow) in a metal are electrons rather than protons because electrons are...

loosely bound.

Electrons are made to flow in a wire when there is...

a potential difference across its ends.

In an ac circuit, the electric field...

changes magnitude and direction with time.

The current through a 10-ohm resistor connected to a 120-V power supply is...

12 A.

The primary source of electrons in an ordinary electrical circuit is...

the electrical circuit itself.

The source of all magnetism is...

moving electric charge.

Moving electric charges will interact, with...

both an electric field and a magnetic field.

An electron is shot through a spot somewhere between the ends of a horseshoe magnet. the electron...

direction is changed.

Which of the following force field can increase a moving electron's speed? A. only an electric field B. either an electric or magnetic field. C. only a magnetic field. D. none of these.

A. only an electric field.

When there is a change in the magnetic field in a closed loop a wire... A. a voltage is induced in the wire. B. a current is created in the loop of wire. C. electromagnetic induction occurs. D. all of the above. E. none of the above.

D. all of the above.

Electromagnetic induction occurs in a coil when there is a change in...

magnetic field intensity in the coil.

Most of the waves in the electromagnetic spectrum are...

invisible.

Electromagnetic waves consist of...

oscillating electric and magnetic fields.

The source of all electromagnetic waves is...

accelerating electric charges

The main difference between a radio wave and a visible light wave is it's...

frequency and wavelength.

Which electromagnetic waves has the shortest wavelength?

X-rays.

Color depends on what characteristics of light?

its frequency.

When the frequency of light matches the natural frequency of molecules in a material, light is...

absorbed.

Light shines on a pane of green glass and a pane of clear glass. The temperature will be higher in the..

green class.

Light is emitted when...

electron clouds of atoms are forced into oscillation.

Light refracts when traveling from air into glass because light...

travels slower in glass than air.

Refraction results from differences in light's

speed.

Different colors are dispersed by a prism because different colors in the prism have different...

speeds.

Consider plane waves incident upon a barrier with a small opening. After passing through the opening, the waves...

fan out.

``` Interference is a property of... A. water waves B. sound waves C. light waves D. all of these E. none of these ```

D. all of these

Polarization is a property of..

transverse waves.

Light will not pass through a pair of Polaroid's when their axes are...

perpendicular.

``` Monochromatic light is light of a single.. A. Frequency B. Wavelength C. Color D. All of these E. None of these ```

D. all of these

To say that energy levels in an atom are discrete is to say the energy levels are well defined and...

separate from one another.

An excited atom is an atom..

that has one or more displaced electrons.

Light is emitted when an electron...

makes a transition to a lower energy level.

An atom that absorbs a photon of a certain energy can then emit...

only a photon of the same or lower energy.

Which color of light carries the most energy per photon?

violet.

The dark lines in the Sun's spectrum represents light that is..

absorbed by the sun's atmosphere.

Green light emitted by excited mercury vapor corresponds to a particular energy transition in the mercury atom. A more energetic transition might emit...

blue light.

The energy of a photon depends on it's....

Frequency

Which radiation has no electric charge associated with it?

gamma rays.

X-rays are similar to..

gamma rays.

Which radiation has a negative electric charge associated with it?

beta rays.

Which radiation has the lowest relative relative penetration through a material...

alpha rays.

The half-life on an isotope is one day. At the end of two tays the amount that remains is...

one-quarter of what you started with.

There is a greater proportion of carbon 14 in...

new bones.