PSC120 - Exam 1 Study Guide

At which of the following Celsius temperatures will a Fahrenheit thermometer show the same reading in degrees?

-40°C

of the following, the shortest is

0.01 in

a centimeter is

0.01 m

The length C of the longest side of a right triangle is related to the lengths A and B of the other sides by the formula

C = sqrt (A^2) + (B^2)

The discovery that the planetary orbits are ellipses rather than circles was made by

Kepler.

the planet closest to the sun is

Mercury

Which of the following statements is correct?

Moving electrons constitute electric currents.

A crane exerts an upward force of 200 N on a 20-kg crate. The crate's upward acceleration is

NOT - 10 m/s 2.

a planet not visible to the naked eye is

Neptune

Which of the following formulas expresses the relationship between the pressure and absolute temperature of a gas sample whose volume is fixed?

P1/T1 = P2/T2

the object in the sky that apparently moves the least in the course of time is

Polaris

Living things

have evolved throughout the earth's history.

the law of gravity

holds everywhere in the universe

A negative electric charge

interacts with both positive and negative charges.

the speed of a planet in its orbit around the sun

is highest when the planet is closest to the sun

the ongoing evolution of living things

is one of the basic concepts of biology

The earth bulges slightly at the equator and is flattened at the poles because

it spins on its axis

The temperature of a gas sample in a rigid container is reduced. The pressure the gas exerts on the container walls decreases because

its molecules have lower average speeds and so strike the walls less often with less momentum.

When the speed of an object is doubled,

its momentum is doubled.

If a shell fired from a cannon explodes in midair,

its total KE increases

On a molecular level heat is

kinetic energy

Which of the following units could be associated with a vector quantity?

km/s^2.

A regularity in observed data or a relationship between different quantities is usually called a

law.

If a spaceship 100 m long when at rest on the earth were to travel at nine-tenths the speed of light, its length as measured by an observer on the earth would be

less than 100 m.

When a gas is forced into a smaller volume without a change in temperature, its pressure increases because its molecules

strike the container walls more often.

which of the following is no longer considered valid?

the Ptolemaic system

Leap years are needed because

the length of the year is not a whole number of days

Which of the following quantities is always the same to all observers?

the speed of light

An object moving in a circle at constant speed is accelerated

toward the center of the circle.

The radius of the path of an object moving in a circle at constant speed is halved. If the speed remains the same, the centripetal force needed is

twice as much as before.

the usual tidal pattern in most parts of the world consists of

two high tides and two low tides

If undisturbed, an electric current in a superconducting wire loop

will continue indefinitely.

A 40-kg boy climbs a vertical ladder at 0.5 m/s. His power output is

196 W.

A nautical mile (nm) is 6076 ft long, and a knot (kn) is a unit of speed equal to 1 nm per hour. How many feet per second does a 10-kn boat move through the water?

17 ft/s

In the first 3 s after a car starts from rest with an acceleration of 4 m/s 2 it will travel

18 m.

The shortest of the following is

0.1 mi.

Which one or more of the following pairs of displacements cannot be added to give a resultant displacement of 2 m?

1 m and 4 m.

of the following, the longest is

1 mi

the prefix micro stands for

1/1,000,000

The measurements of a room are given as length = 5.28 m and width = 3.1 m. Since (5.28)(3.1) = 16.368, the room's area is correctly expressed as

16 m^2

Two charges, one positive and the other negative, are initially 2 cm apart and are then pulled away from each other until they are 8 cm apart. The force between them is now smaller by a factor of

16.

The specific heat of water is 4.2 kJ/kg°C. The heat needed to warm 8 kg of water from 20°C to 70°C is

1680 kJ.

The primary coil of a transformer has 200 turns and its secondary coil has 50 turns, and the current in the secondary coil is 40 A. When a 12-V alternating current is applied to the primary coil of the transformer, the secondary voltage will be

3 V.

The speed of a 1000-kg car whose KE is 450 kJ is

30 m/s

Arrange the following planets in the order of their distance from the sun.

4, 1, 3, 2

In order to double the average energy of the molecules in a gas at 200 K, its temperature must be changed to

400 K.

A ship travels 20 km to the south and then 40 km to the west. The ship's displacement from its starting point is

45 km.

A 50-kg person weighs

490 N.

a person is 180 cm tall. this is equivalent to

5 ft 11 in

Six kJ of work is used to lift an object to a height of 100 m. The object's approximate mass is

6 kg.

Which of the following sets of displacements might be able to return a car to its starting point?

60, 120, 180, and 240 km.

A current-carrying wire is in a magnetic field with the direction of the current perpendicular to that of the field.

The wire tends to move perpendicular to the field.

the scientific method is

a continuing process

a hypothesis is

a new scientific idea

an constellation is

an apparent pattern of stars in the sky

a scientific law or theory is valid

as long as it is not contradicted by new experimental findings

The sun

attracts light waves passing nearby.

When a magnetized iron bar is strongly heated, its magnetic field

becomes weaker.

In order to operate, a heat engine must have

both a hot and a cold reservoir.

When an observer moves past a stationary electric charge, she detects

both an electric and a magnetic field.

high tide occurs at a given place

both when the moon faces the place and when the moon is on the opposite side of the earth from the place

tides are caused

by both the sun and the moon

Heat transfer in a vacuum

can take place only by radiation.

Which of the following quantities is independent of the size and shape of an object composed of a given material?

density

The properties of several different materials are being compared. If the samples all have the same volume, the one with the greatest mass also has the greatest

density.

According to Kepler's third law, the time needed for a planet to complete an orbit around the sun

depends on the planet's distance from the sun

Kepler modified the Copernican system by showing that the planetary orbits are

ellipses

A kilowatt hour is a unit of

energy

The stars in a constellation

form a pattern in the sky as seen from the earth.

The period of the earth's orbit around the sun is

one year.

A current-carrying loop in a magnetic field always tends to turn until the plane of the loop is

parallel to the field.

A rocket is fired in space. As it moves, the total momentum of the rocket and its exhaust gases

remains the same.

Gravity is not

responsible for holding atoms and molecules together.

The length of the year is

slightly more than 365 days.