Issues in Science tech and Society tests over semester 2021

Absolute zero corresponds to a temperature of

0 K and -273 C

A 30-kg girl and a 25-kg boy face each other on friction-free roller blades. The girl pushes the boy, who moves away at a speed of 1.0 m/s. The girl's speed is

0.833 m/s

A horizontal force of 100 N is required to push a crate on a horizontal surface at a constant velocity. The weight of the crate is 40 kg. What is the frictional force on the crate?

100 N

A ball is moving at 4 m/s and has a momentum of 48 kg∙m/s. What is the ball's mass?

12 kg

A shopping cart moves with a kinetic energy of 40 J. If it moves at twice the speed, its kinetic energy is

160 J

A 1000-kg car moving at 10 m/s that brakes to a stop in 5 s has an average braking force of

2000 N

The electric power of a lamp that carries 2 A at 120 V is

240W

An electronic game requires 6 V for operation. A transformer allows it to be powered from a 120-V outlet. If the primary has 500 turns, the secondary has_______ turns.

25

The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?

26

A music console is pushed a distance of 2 m with a force of 20 N. The work done on the console is

40 J

If a material has a half-life of 24 hours, how long do you have to wait until the amount of radioisotope is 1/4 its original amount?

48 hours

A school bus slows to a stop with an average acceleration of -2.0 m/s2. The bus has an initial speed of 10.0 m/s. How long will it take the bus to come to a stop?

5 sec

A diver who weighs 500 N steps off a diving board 10 m above the water hits the water with kinetic energy of

5000 J

A 5000-kg freight car crashes into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg freight car?

6 m/s

A resistor carries a current of 2 A when connected to a 12-V battery. It has a resistance of

6 ohms

A ball is thrown straight up with a velocity of 40 m/s. How long does it hang in air?

8 sec

A 1-kg ball (ball A) coming from left collides with a 2-kg ball (ball B) coming from the right. A was travelling with speed 1 m/s and B was travelling with speed 2 m/s. They are travelling in opposite direction towards each other. At the time of collision:

A and B will apply the same force on each other but in opposite direction

Which of the following best explains what is happening when an atom emits light?

An electron is dropping from a higher to a lower energy level with the difference in energy between the two being emitted as light.

Newton's First Law states that:

An object will not change velocity unless there is a net force

A bowling ball rolling along a lane gradually slows as it rolls. How would Aristotle interpret this observation?

Rest is a natural state of things

Which would cause a more serious burn: 30 g of steam or 30 g of liquid water both at 100 o C

Steam, because of its extra heat of vaporization

Which of the following statements about fission is true?

The amount of energy released in the fission of large nuclei is very large.

The force that lifts a rocket during its launch is provided by:

The fact that the rocket pushes the exhaust gas out, and the exhaust gas pushes the rocket in opposite direction

Which of the following statements best describes the strong nuclear force?

The force is very strong but has a very short range.

Weight of an object is defined as:

The force with which Earth attracts the object

The condition of equilibrium means:

The net force on an object is zero

Inertia can be defined as

The property by which an object resist changing motion

Acceleration is defined as:

The rate at which an object's velocity changes

You pull the end of a spring attached to a wall. The reaction to your pull is:

The spring pulling on you

Consider your desk at rest on your bedroom floor. As you and your friend try to lift it (before it finally loses contact with the floor) which of the following statements will be true?

The support force on the desk decreases and support force on your feet increases

Does it make sense to say that a textbook is about 99.9 percent empty space?

Yes. A textbook like all material things is made up of atoms, which are considered to be 99.9 percent empty space.

Which of these statements is true?

a battery produces dc and a generator produces ac

If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?

atomic mass, 99 amu; Technetium

As entropy in a system increases, energy within the system

becomes less ordered

Heat energy is measured in units of

both joules and calories

The transfer of heat by convection will occur

by movement of fluid

A nutritionist in the United States measures the food energy in units of

calories

If two protons and two neutrons are removed from the nucleus of an oxygen atom, a nucleus of which element remains?

carbon-12

A neutron makes a better nuclear bullet than a proton or an electron because it

carries no electrical charge

Magnetic field lines about a current-carrying wire

circle the wire in closed loops

________is the type of thermal energy transfer that occurs when the you place a cooler object on a heat source to warm the cooler object up.

conduction

Earth's magnetic field affects cosmic rays by

deflecting them

Which of the following sources of radiation provides most of our yearly exposure?

dental and medical X-rays

A parachutist falling at constant velocity is in a state of

dynamic equilibrium

Radiation is the process in which energy is transferred by means of

electromagnetic waves

Which of the following statements describes an isotope?

element with the same number of protons but a different number of neutrons

Radioactivity is a tendency for an element or a material to ________.

emit radiation

An electron de-excites from the fourth quantum level to the third and then directly to the first. Two frequencies of light are emitted. How do their combined energies compare to the energy of the single frequency that would be emitted by de-excitation from the fourth level directly to the first level?

equal to the energy of the single frequency.

Which law of thermodynamics is a restatement of the conservation of energy as it applies to thermal systems?

first law

Which type of radiation: alpha, beta, or gamma results in the no change in atomic number?

gamma radiation

Elements that are in the same ________ have a tendency to have very similar chemical properties due to periodic trends

group

To say a circuit is dc is to say that current in the circuit

has a single direction

Compared to a giant iceberg, a hot cup of coffee has

higher temperature, but less thermal energy

If gravity between the Earth and the Moon suddenly vanished, Moon will continue its motion

in a straight line

Stretch a copper wire so that it is thinner and the resistance between its ends

increases

Because a refrigerator operates with some kind of motor, leaving the refrigerator door open

increases room temperature

Your room gets messier day by day. In this case entropy is

increasing

Magnetic domains normally occur in

iron

When the distance between two charges is doubled, the electric force between the charges

is reduced to one-quarter

The ecliptic

is the plane of Earth's orbit

If a charging rhinoceros has momentum, it must also have

kinetic energy

Water at 4°C will sink to the bottom of a pond because

like a rock, it is denser than surrounding water

You're driving down the highway and a lovebug spatters onto your windshield. Which undergoes the greater impulse?

lovebug has more

When a cannon fires a cannonball at a given speed, the smaller recoil speed of the cannon is due to different

masses

The source of all magnetism is

moving electric charge

What type of charge produces the electric field that points inward?

negative

The power expended for a barbell raised 2.0 m in 2 s is

not enough information

Which of the four states of matter occurs at the highest temperature?

plasma

The nucleus of an atom is charged

positively

When water changes to ice, water molecules

release energy

When steam condenses to water, energy is

released

Which law of thermodynamics addresses the direction of heat flow?

second law

The resistive force of friction occurs for

solids, liquids, and gases

San Francisco has milder winters than Washington D.C. due to water's high

specific heat capacity

From the same height you simultaneously drop a lightweight tennis ball and a heavyweight bowling ball. When they hit the floor they have the same

speed

The average kinetic energy of molecules in an object are directly related to the

temperature

Heat is thermal energy that flows due to

temperature differences

A proton and an electron are placed in an electric field. Which undergoes the greater acceleration?

the electron

No work is done by gravity on a bowling ball that rolls along a bowling alley because

the force on the ball is at right angles to the ball's motion

A cloud of interstellar gas is held together by

the gravitational force

In order to catch a fast-moving softball with your bare hand, you extend your hand forward just before the catch and then let the ball ride backward with your hand. Doing this reduces the catching force because the

time of catch is increased

When a magnet is thrust into a coil that has twice the number of loops, the induced voltage is

twice as much

When you stand at rest on a floor, the number of vertical forces acting on you

two

When we say charges are "positive" or "negative" we are speaking of

two intrinsically different charges found in nature

Every magnet contains at least

two poles

A step-down transformer decreases

voltage

Condensation is a......

warming process

Which of the following expands most when the temperature is lowered? Equal volumes of

water at 4°C

Madison pushes with a 120-N horizontal force on a 20 kg crate on a warehouse floor. The force of friction on the crate is 80-N. The crate will:

Have acceleration of 2 m/s2

A net force on a box is causing it to accelerate. If you throw in some mass in the box while it is moving (making the mass now triple) the box will:

Have one third the acceleration as before

As you leap upward from the ground, how does the force that you exert on the ground compare to your weight?

It is greater than your weight

Which of the following statements does not describe a proton?

It orbits around the nucleus of an atom

The scientific unit for force is:

Newton

Which of the following statements about radiation is true?

Radiation can be a useful tool. Like fire, it is only dangerous when misused.

Which atom is largest?

Rb

You drop a rock from the rooftop of a building. While it falls (without air friction)

Its speed increases but acceleration remains the same

Which statement about magnetic poles is NOT correct?

Magnetic monopoles behave like isolated electric charges

If you throw a ball upwards its velocity decreases until it reaches the maximum height. At the top its velocity is zero. At that point the acceleration of the ball is:

Downward and 9.8 m/s2

In some instances electromagnetic radiation behaves like a wave. In other instances electromagnetic radiation behaves more like a particle. Which behavior more accurately describes the true nature of electromagnetic radiation?

Electromagnetic radiation behaves both as a wave or as a particle depending on the circumstance.

If you drop an object from a height its acceleration downward is 9.8 m/s2. Instead of dropping it you throw it down with a significant initial speed. The acceleration of the object will be:

Equal to 9.8 m/s2