Physics final-Exam 3 review Flashcards

Water pressure is greatest against the

a. bottom of a submerged object

b. is the same against all surfaces

c. top of a submerged object

d. sides of a submerged object

e. none of these

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

a. it looks better

b. surface tension exists only at the surface of liquids

c. water pressure is greater with increasing depth

d. water is denser at deeper levels

e. none of these

The pressure at the bottom of a jug filled with water does NOT depend on

a. water density

b. the height of the liquid

c. surface area of the water

d. the acceleration due to gravity

e. none of these

A completely submerged object always displaces its own

a. weight of fluid

b. density of fluid

c. volume of fluid

d. all of these

e. none of these

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

a. more than 10 tons

b. 10 tons

c. depends on density of sea water

d. less than 10 tons

What is the weight of water displace by a 100 ton floating ship

a. 100 tons

b. depends on the ship's shape

c. more than 100 tons

d. less than 100 tons

e. 100 cubic meters

The buoyant force on an object is least when the object is

a. submerged near the bottom

b. partly submerged

c. submerged near the surface

d. none of these

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

a. by a force equal to its own weight

b. and floats because of Archimedes principle

c. but nevertheless sinks

d. by a force equal to the weight of liquid displace

e. none of these

Two life preservers have identical volume, but one is filled with Styrofoam while the other is filled with sand. When the two life preservers are fully submerged, the buoyant force is greater on the one filled with

a. sand

b. Styrofoam

c. same on each as long as their volumes are the same

Compared to an empty ship, the same ship loaded with Styrofoam will float

a. at the same level in the water

b. higher in the water

c. lower in the water

Two equal sized buckets are filled to the top with water. One of the buckets has a piece of wood floating in it, making its total weight

a. less than the weight of the other bucket

b. more than the weight of other bucket

c. equal to the weight of the other bucket

Compared to the buoyant force that acts on you when you float in fresh water, the buoyant force that acts on you when you float in the dense water of the Dead Sea is

a. more, because of the greater density of fluid displaced

b. less, because less of your volume is displaced

c. the same

A rock suspended by a string weighs 5N out of water and 3N when submerged. What is the buoyant force on the rock?

a. 3N

b. 2N

c. 8N

d. 5N

e. none of these

In a hydraulic-press operation, it is impossible for the

a. force output to exceed the force input

b. output piston's speed to exceed the input piston's speed

c. output displacement to exceed the input displacement

d. energy output to exceed the energy input

e. none of these

The ration of output force to input force of a hydraulic press will be equal to the ratio of the output and input piston

a. diameters

b. radii

c. areas

d. all of these

e. none of these

To multiply the input force of a hydraulic lift, the input end should be the one having the

a. smaller diameter piston

b. larger diameter piston

c. Relative piston sizes don't matter

Substances absorb heat energy by the process of

a. convection

b. conduction

c. radiation

d. all of these

A good heat conductor is

a. a poor insulator

b. a good insulator

c. neither a poor nor a good insulator

Your feet fell warmer on a rug than on a tile floor because a rug

a. is a better insulator than tile

b. for the same mass has more internal energy than tile

c. is usually warmer than tile

d. all of these

e. none of these

Warm air rises because faster-moving molecules ten to move to regions of less

a. pressure

b. density and less pressure

c. density

Objects that radiate relatively well

a. reflect radiation relatively well

b. absorb radiation relatively well

c. both of these

d. neither of these

A liter of hot water will cool to room temperature faster in a

a. red pot

b. silver pot

c. black pot

d. depends on the size of the pot than its color

Cold water will warm to room temperature faster in a

a. silver pot

b. black pot

c. depends more on the size of the pots than their color

Which body glows with electromagnetic waves?

a. only the Earth

b. neither the Sun or the Earth

c. only the Sun

d. both the Sun and the Earth

The planet Earth loses heat mainly by

a. radiation

b. conduction

c. convection

d. all of these

If air were a better conductor than it is, at nighttime the Earth would be

a. considerable warmer

b. not appreciably different in temperature

c. considerable cooler

A water-filled paper cup held in a flame will not catch fire. This is because

a. paper is a poor conductor of heat

b. inside the paper is wet

c. water is an excellent conductor of heat

d. the paper cup cannot become appreciable hotter than the water it contains

One of the main reasons one can walk barefoot on red-hot coals of wood without burning the feet has to do with

a. low thermal conductivity of the coals

b. mind over matter techniques

c. low temperature of the coals

Hydrogen and oxygen molecules in a gas sample have the same temperature. This means the hydrogen molecules, on the average, have the same

a. speed, but less kinetic energy

b. kinetic energy, but less speed

c. speed, but more kinetic energy

d. kinetic energy, but more speed

e. speed and the same kinetic energy

A wiggle in time is a

a. wave

b. vibration

c. both

d. neither

Like a transverse wave, a longitudinal wave has

a. amplitude, frequency and speed

b. wavelength, speed and frequency

c. amplitude, frequency, wavelength and speed

d. amplitude, wavelength and speed

e. amplitude, frequency and wavelength

In a longitudinal wave the compression and rarefactions travel in

a. a vacuum

b. the same direction

c. opposite directions

Which of the following is not a transverse wave?

a. radio

b. sound

c. light

d. all of these

e. none of these

How many vibrations per second are associated with a 101 MHz radio wave

a. 101,000,000

b. more than 101,000,000

c. less than 101,000,000

Radio waves travel at the speed of light, 300,000 km/s. The wavelength of a radio wave received at 100 megahertz is

a. 300m

b. 0.3m

c. 30m

d. 3.0m

e. none of these

The frequency of a simple pendulum depends on

a. the acceleration due to gravity

b. its length

c. its mass

d. all of these

e. two of these

If the frequency of a certain wave is 10 hertz, its period is

a. 10 seconds

b. 0.1 second

c. 100 seconds

d. none of the above choices are correct

Wave interference occurs for

a. water waves

b. light waves

c. sound waves

d. all of the above choices are correct

e. none of the above choices are correct

A node is a position of

a. maximum amplitude

b. half amplitude

c. minimum amplitude

The Doppler effect is characteristic of

a. sound waves

b. light waves

c. water waves

d. all of the above choices

e. none of the above choices

A Doppler effect occurs when a source of sound moves

a. towards you

b. in a circle around you

c. either towards you or away from you

d. away from you

If you double the frequency of a vibrating object, its period

a. doubles

b. is quartered

c. halves

A wave travels an average distance of 1 meter in 1 second with a frequency of 1 hertz. Its amplitude is

a. 1 meter

b. more than 1 meter

c. less than 1 meter

d. not enough information to say

During a single period, the distance traveled by a wave is

a. one-half wavelength

b. two wavelengths

c. one wavelength

A weight suspended from a spring bobs up and down over a distance of 1 meter in two seconds. Its frequency is

a. 1 hertz

b. 0.5 hertz

c. 2 hertz

d. none of the above choices are correct