Chp 9/10 PHY

Your flashlight has three identical 1.5 Volt batteries in it, arranged in a chain to give a total of 4.5 Volts. Current passes first through the first battery, then through the second battery, then through the third, on its way to the bulb. When you operate the flashlight, the batteries provide power to the flowing charges and they gradually use up their chemical potential energy. Which battery will run out of chemical potential energy first?

All three will run out at the same time.

How does an object bobbing on a water wave move?

Circular motion

For an appliance to receive and consume electric power,

a current must flow through it across a voltage decrease.

When you blow gently across the top of a particular soda bottle, it emits a tone. The column of air in the bottle is vibrating up and down in its fundamental mode. If you replace the air in the bottle with helium and then blow gently across the top of the bottle, it will emit

a higher pitched tone.

In further studying physics, you learn that light and particles have a dual nature, with light behaving like particle and vice versa. A particle (quantum) of light is called

a photon.

The strings of a guitar vibrate at different frequencies. They have different thicknesses because

a thicker, more massive string vibrates at a lower frequency than a thinner string of the same length and tension.

The reason for using a harmonic oscillator as a clock's time-keeper is so that the clock will keep accurate time even if the

amplitude of the time-keeper's oscillation changes.

A guitar string that normally vibrates with a fundamental frequency of 110 Hz is also capable of vibrating at 330 Hz. When that higher frequency vibration occurs, the string is vibrating

as 3 strings that are one third as long as the overall string.

A positive charge and a negative charge will

attract each other.

On a warm, balmy summer day you decide to relax by watching the latest building renovation in your neighborhood. You notice that a very heavy wrecking ball is attached to a much lighter chain and is dangling from a crane and swinging back and forth. As long as it does not swing too high the time it takes the wrecking ball to complete one full oscillation will be independent of

both the amplitude of the motion and the weight of the ball.

In a closed circuit,

current flows normally.

Your cat has chewed the cord to your desk lamp and has created a short circuit—an electric connection from one wire to the other inside the cord. When you plug the lamp into the electric outlet,

current will bypass the bulb and the bulb will not light up.

A battery works because it

pumps positive charge from its negative terminal to its positive terminal.

You stick two pieces of adhesive tape on a glass window and then pull them off suddenly. If you now hold the tape pieces near each other, they will be

repelled because they have like charges.

You are a superb proposal writer and convince NASA to fund your taking a pendulum clock to Mars and studying how it runs. Compared to the time it should keep on Earth, the clock will run

slower.

You notice that two charges are exerting a certain force on one another. If the distance between two electric charges doubles, then the force they exert on each other changes by how much?

1/4 as large

Who originally named electric charges as positive and negative?

Benjamin Franklin

How are standing waves and traveling waves similar?

Both waves involve oscillation of some medium.

What does the period of a pendulum depend on?

Length and gravity.

Suppose a water wave strikes a very large solid barrier, such as a cliff. The wave will redirect its motion through

Reflection

What bridge collapse in 1940 was due to a resonant energy transfer?

Tacoma Narrows Bridge

Why does a tidal cycle take more than 12 hours?

The Moon orbits the Earth

Suppose you "think outside the box" and design a guitar with strings which all have the same thickness, length and density. Which of the following designing issues must you also consider?

The strings must be able to withstand a wide range of tensions in order to produce the notes needed.

Why does the tide get so high in the Bay of Fundy?

There is a natural resonance of water motion there.

The waves produced by plucking a guitar string are

Transverse

If you blow across the top of a half full bottle of soda you can produce a clear tone. If you take a drink of soda to reduce the amount of liquid in the bottle and try this again the pitch (frequency) of the sound produced will

decrease

You have just pulled your clothes from the dryer and find that a sock is clinging to your jeans with static electricity. You hold the jeans in one hand and the sock in the other and pull the two apart. As jeans and sock move apart, the forces between them become weaker because the

distance between the garments increase.

Semiconductors

do not obey Ohm's law.

In a flashlight bulb, the brightness of the light bulb is a direct indication of

electric current through it.

After running a plastic comb through your hair several times you hold it above a small scrap of paper. The paper jumps off the table and sticks to the comb because the paper becomes

electrically polarized.

Good electrical conductors are usually good thermal conductors because

electrons are responsible for thermal and electric conduction.

In a short circuit,

electrons can take a short cut.

In the dark, the photoconductors used in most xerographic copiers are

insulators.

One reason for using a quartz crystal as a clock's time-keeper is so that the clock will

keep accurate time even if the ambient temperature changes.

A photoconductor's electrical properties go from insulating to conducting when it is exposed to light because,

light supplies the energy needed to move electrons from the valence band to the conduction band.

The surface of a photoconductor has been coated with electric charge. This charge will remain in place until you expose the surface to

light.

You are a superb proposal writer and convince NASA to fund your taking a pendulum clock to Mars and studying how it runs. Compared to how it would be on Earth, the time it takes for the pendulum to compete one cycle will be

longer.

Electrons are

much lighter than protons.

In an open circuit,

no current flows.

The tides are strongest near the equator because that is where the

tidal bulges caused by the moon are tallest.

Water can support

traveling and standing waves.

You decide to help your physics professor do an interactive classroom demonstration. You are standing on a plastic bench that insulates you from your surroundings. Both you and the helium balloon you are holding are electrically neutral. You now rub the balloon against your sweater, so that the balloon becomes negatively charged, and then let the balloon float away. You are left

with a positive electric charge.

A harmonic oscillator is an oscillator

with a restoring force proportional to its displacement from equilibrium.

You remove the batteries from a working flashlight, turn both of them around as a pair, and reinsert them in the flashlight. They make good contact with the flashlight's terminals at both ends, so that there is no mechanical problem preventing the flashlight from working. If you now switch on the flashlight, it will

work properly, although current will now be flowing backward through its circuit.

You are installing a new battery in your car. Although there are two terminals on the battery you hook up only one of your car's battery cables to the battery. Hooked up like this, the current that would then flow through the headlights when turned on is

zero.