Phys 1050 exam one

Which of these is a scientific hypothesis?

A. The Moon is made of green cheese.

B. Atomic nuclei are the smallest particles in nature.

C. A magnet will pick up a copper penny.

D. Cosmic rays cannot penetrate the thickness of your Conceptual Physics textbook.

All

Which of these is not a scientific hypothesis?

A. Protons carry an electric charge.

B. Undetectable particles are some of nature's secrets.

C. Charged particles bend when in a magnetic field.

D. All of the above are scientific hypotheses.

B. Undetectable particles are some of nature's secrets.

Which of these often changes over time with further study?

A. Facts. B. Theories. C. Both of the above. D. Neither of the above.

C. Both of the above

A person who says, "that's only a theory" likely doesn't know that a scientific theory is a

A. guess.

B. number of facts.

C. hypothesis of sorts.

D. vast synthesis of well-tested hypotheses and facts.

D. vast synthesis of well-tested hypotheses and facts.

Although physics may be the most difficult science course in certain schools, when compared with the fields of chemistry, biology, geology, and astronomy, it is

A. the simplest.

B. still the hardest!

C. the central science, between chemistry and biology.

D. simple enough, but only for especially intelligent people.

A. the simplest.

Which of the following are incorrect statements about the atom?

A.Atoms are smaller than the wavelength of visible light.

B.Atoms are mostly empty space, just as the solar system is mostly empty space.

C.Atoms are perpetually moving.

D.Atoms are manufactured in plants, and in humans during pregnancy.

E.All are correct.

D.Atoms are manufactured in plants, and in humans during pregnancy.

The atomic number of an element matches the number of

A.protons in the nucleus of an atom.

B.electrons in a neutral atom.

C.Both of the above.

D.None of the above.

C.Both of the above.

A nucleus with an atomic number of 44 and a mass number of 100 must have

A.44 neutrons.

B.56 neutrons.

C.100 neutrons.

D.All of the above.

B.56 neutrons.

Suppose you drill a hole horizontally through a tree branch as shown. Where will the hole weaken the branch the least?

A.Near the top

B.Near the bottom

C.Near the middle

D.It does not matter.

C.Near the middle

When you stand on one foot instead of two, the force you exert on the floor is

A.less.

B.the same.

C.more.

D.None of the above.

B.the same.

When you stand on one foot instead of two, the pressure you exert on the floor is

A.less.

B.the same.

C.more.

D.None of the above.

C.more.

Water pressure provided by a water tower is greater if the tower

A.is taller.

B.holds more water.

C.Both A and B.

D.None of the above.

A.is taller.

How many forces act on a submerged body at rest in a fluid?

A.One—buoyancy

B.Two—buoyancy and the force due to gravity

C.None—in accord with the equilibrium rule, SF = 0

D.None of the above.

B.Two—buoyancy and the force due to gravity

When a submarine takes water into its ballast tanks, its density

A.decreases.

B.increases.

C.remains the same.

D.None of the above.

B.increases.

When a submerged submarine expels water from its ballast tanks, its density

A.decreases.

B.increases.

C.remains the same.

D.None of the above.

A.decreases.

You place an object in a container that is full to the brim with water on a scale. The object floats, but some water spills out. How does the weight of the object compare with the weight of the water displaced?

A.Weight of object is greater than weight of water displaced.

B.Weight of object is less than weight of water displaced.

C.Weight of object is equal to weight of water displaced.

D.There is not enough information to decide.

C.Weight of object is equal to weight of water displaced.

Two solid blocks of identical size are submerged in water. One block is lead and the other is aluminum. Upon which is the buoyant force greater?

A.On the lead block

B.On the aluminum block

C.Same on both blocks

D.There is not enough information to decide.

C.Same on both blocks

The maximum height to which water can be drunk through a straw

A.is 10.3 m.

B.is about 76 cm.

C.has no limit.

D.None of the above.

A.is 10.3 m.

Why don't barometers use water instead of mercury?

A.Water cannot be used because it does not exert pressure.

B.Water cannot be used because it sticks to the glass.

C.Water can be used but the barometer will be too tall.

D.None of the above.

C.Water can be used but the barometer will be too tall.

A piston in an airtight pump is withdrawn so that the volume of the air chamber is increased 3 times. What is the change in pressure?

A.The pressure is 3 times the original pressure.

B.The pressure is 1/3 the original pressure.

C.The pressure does not change.

D.There is not enough information to figure this out.

B.The pressure is 1/3 the original pressure.

A dirigible that hovers in air

A.displaces its volume of air.

B.displaces its weight of air.

C.Both A and B.

D.None of the above.

C.Both A and B.

The pressure in a stream of water is reduced as the stream speeds up. Can a stream of water from a fire hose actually knock a person off his or her feet?

A.It can't, as Bernoulli's principle illustrates.

B.It can, and is consistent with Bernoulli's principle.

C.Bernoulli's principle works only for laminar flow, which the stream is not.

None of the above.

B.It can, and is consistent with Bernoulli's principle.

On a windy day, waves in a lake or the ocean are higher than their average height. What factor in Bernoulli's principle contributes to the increased height?

A.Reduced pressure pulls water upward.

B.Pressure builds up over the crests.

C.Air travels faster over the crests than the troughs.

D.None of the above.

C.Air travels faster over the crests than the troughs.

There is twice as much molecular kinetic energy in 2 liters of boiling water as in 1 liter of boiling water. Which will be the same for both?

A.Temperature

B.Thermal energy

C.Both A and B.

D.Neither A nor B.

A.Temperature

To say that body A has a higher temperature than body B is to say that body A has more

A.internal energy.

B.mass.

C.kinetic energy per particle.

D.potential energy.

C.kinetic energy per particle.

If a red-hot thumbtack is immersed in warm water, the direction of heat flow will be from the

A.warm water to the red-hot thumbtack.

B.red-hot thumbtack to the warm water.

C.There will be no heat flow.

D.Not enough information.

B.red-hot thumbtack to the warm water.

The same quantity of heat is added to different amounts of water in two equal-size containers. The temperature of the smaller amount of water

A.decreases more.

B.increases more.

C.does not change.

D.Not enough information.

B.increases more.

You heat a half-cup of tea and its temperature rises by 4ºC. How much will the temperature rise if you add the same amount of heat to a full cup of tea?

A.0ºC

B.2ºC

C.4ºC

D.8ºC

B.2ºC

Which has the higher specific heat capacity, water or land?

A.Water

B.Land

C.Both of the above are the same.

D.None of the above.

A.Water

When stringing telephone lines between poles in the summer, it is advisable to allow the lines to

A.sag.

B.be taut.

C.be close to the ground.

D.allow ample space for birds.

A.Sag

When a sample of 0ºC water is heated, it first

A.expands.

B.contracts.

C.remains unchanged.

D.Not enough information.

B.contracts

When a sample of 4ºC water is cooled, it

A.expands.

B.contracts.

C.remains unchanged.

D.Not enough information.

A.expands

If you hold one end of a metal bar against a piece of ice, the end in your hand will soon become cold. Does cold flow from the ice to your hand?

A.Yes

B.In some cases, yes

C.No

D.In some cases, no

C.No

The surface of Earth loses energy to outer space due mostly to

A.conduction.

B.convection.

C.radiation.

D.radioactivity.

C.radiation

Which body glows with electromagnetic waves?

A.Sun

B.Earth

C.Both A and B.

D.None of the above.

C.Both A and B

If a good absorber of radiant energy were a poor emitter, its temperature compared with its surroundings would be

A.lower.

B.higher.

C.unaffected.

D.None of the above.

B.higher

A hot pizza placed in the snow is a net

A.absorber.

B.emitter.

C.Both A and B.

D.None of the above.

B.emitter

Which melts faster in sunshine—dirty snow or clean snow?

A.Dirty snow

B.Clean snow

C.Both A and B.

D.None of the above.

A.Dirty snow

Which is the better statement?

A.A black object absorbs energy well.

B.An object that absorbs energy well is black.

C.Both say the same thing, so both are equivalent.

D.Both are untrue.

B.An object that absorbs energy well is black.

It is commonly thought that a can of beverage will cool faster in the coldest part of a refrigerator. Knowledge of Newton's law of cooling

A.supports this knowledge.

B.shows this knowledge is false.

C.may or may not support this knowledge.

D.may or may not contradict this knowledge.

A.supports this knowledge.