GSCI Quiz #6

You are working late in the physics lab, where you measure the period of a pendulum to be 0.8 s. You fall asleep and have a dream that you are on a planet whose gravitational strength is 4 times that of the earth. If your dream is to be physically accurate, the period of the pendulum in your dream must be

0.4 seconds

As waves move into shallow water, what 3 things happen?

1) The height of the waves increase 2) Their circular orbits become more elliptical as the wave starts to "feel the bottom 3) The wavelength of the waves decrease

An ideally efficient freezer cools food to 210K. If room temperature is 300K, and the machine consumes 75 J of work, how much heat was removed from the food?

175 J

You work in a clock shop and are dealing with an irate customer whose clock you are restoring. They notice that the period of the pendulum in their clock is 2 s and they want to double it. So they insist that you replace the pendulum with one of the same dimensions but just heavier. So you do this. When you get the clock repaired, you and the customer check out the clock's period and find it to be

2 seconds. The mass of the time keeper doesn't influence the period of a pendulum.

An ideally efficient steamboat engine operates on 550 K steam in 300 K weather. How much work can it obtain when 1200 J of heat leaves the steam?_____ How much heat is being added to the cold air outside?_______

545 J; 655 J

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

How does an object bobbing on a water wave move?

Circular motion

________ supplies part of the energy to a pendulum clock, while _________ supplies most of the energy for a balance clock.

Gravity; a spring

You are with a friend playing in the waves at the beach. A large wave is heading straight for you and you don't want to be hit by all that wave energy. You make a split second decision to dive under the wave. You come out on the other side unscathed while your friend gets pummeled by the wave. Your friend is impressed and wants to know how you made it though that wave. You credit your physics teacher for teaching you about beach waves and say...

I simply dove under the wave base where the water no longer feels the energy of the wave.

A Diesel engine is more efficient that a gasoline engine because

It has a higher temperature and can therefore convert more heat into work.

The larger the temperature difference between hot and cold, the ________ the fraction of heat you can divert and transform into __________.

Larger; work

What does the period of a pendulum depend on?

Length and gravity.

You are a superb proposal writer and convince NASA to fund your taking a pendulum clock to Mars and studying how it runs. Remember, the force due to gravity is very small compared to that of Earth. Compared to how it would be on Earth, the time it takes for the pendulum to compete one cycle will be

Longer

During a Spring tide, the moon is in what phase?

New or full.

You decide to attend an amusement park which has a ride where you are strapped into a chair which is in turn firmly attached to a plastic cable. You are released and you bounce up and down as a harmonic oscillator—a mass on the end of spring. Next in line is somebody who weighs twice as much as you do. When the heavier person goes on the ride, you notice that

The heavier rider will have a longer period than the lighter one.

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

There is a natural resonance of motion there.

How can you reduce knocking (have its fuel/air mixture ignite too early) in you car's engine?

Use higher-octane gasoline

A harmonic oscillator is an oscillator?

With a restoring force proportional to its displacement from equilibrium.

Panama is a narrow country that is bounded on the west by the Pacific Ocean and on the east by the Atlantic Ocean. When it is high tide on Panama's Atlantic side, it is

high tide on Panama's Pacific side.

The "strokes", or "cycles," in a four-stroke engine are

induction, compression, power, exhaust

It is a warm summer day and you are having lunch outdoors on a patio. A window air conditioning unit hums quietly nearby as it cools an office inside the building. Your friend notices that the unit's outdoor part is emitting a considerable amount of heat and comments on how strange that is. You explain correctly that the air conditioner's outside part is emitting the heat

it removes from the inside air and the heat it produces from the electricity it consumes.

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.

During a neap tide, the tidal range is typically

smaller than it is at any other time of the month.

Moments before it is ignited by the spark plug, the mixture of fuel and air inside an automobile cylinder is compressed to very high density. During the compression process, the mixture's

temperature rises dramatically and so does its pressure.

The gravitational force between the Moon and Earth depends on

their masses and how far apart they are