Physical Science Chapter 1, 2, 3 Test Reveiw

A car moving at 15 m/s comes to a stop in 10 s. Its acceleration is

-1.5 m/s2.

A 2-kg book is held 1 m above the floor for 50 s. The work done is

0

The longest of the following is A. 1 mm. B. 0.00001 km. C. 0.01 in. D. 0.001 ft.

0.00001 km

A meter is not equal to: A. 100 cm. B. 103 mm. C. 0.01 km. D. 10-3 km.

0.01km

A centimeter is

0.01m

The shortest of the following is

0.1mi

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

A net force of 10 N gives an object an acceleration of 5 m/s2. What net force would give the same object an acceleration of 1 m/s2?

2N Work: 10=m5 -->m=2 F=2(1) --> a=2 F=ma

A ball whose momentum is mv strikes a wall and bounces off. The change in the ball's momentum is

2mv

A square foot contains approximately

929 cm^2

Which one or more of the following is a vector quantity?

Both A and B

A moving object must have which one or more of the following?

Both B, C, and D

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=(square root)a^2+b^2

Relative to the stars, the moon seems to move

Eastward

The speed of an object moving in a circle is doubled. The centripetal force needed is

Four times as much as before

The idea that all conclusions about the natural world must be based upon experiment and observation was first emphasized in the work of

Galileo.

When a planet is farthest from the sun in its orbit

Its speed is at its least

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

Kepler

The formula KE = ½mv^2 for kinetic energy

NOT:is the correct formula if v is properly interpreted.

The scientist who showed that gravity accounts for Kepler's laws of planetary motion was

Newton

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

One Year

The object in the sky that lies very nearly on an extension of the earth's axis is

Polaris

The watt is a unit of

Power

A force gives a 100-kg mass an acceleration of 2 m/s2. The same force would give a mass of 1000 kg an acceleration of

0.2 m/s2

A 100-kg astronaut ejects 4 g of gas from her propulsion pistol at a speed of 50 m/s. Her recoil speed is

0.2mm/s

A certain force gives a 5-kg object an acceleration of 2.0 m/s2. The same force would give a 20-kg object an acceleration of

0.5 m/s^2

A car starts from rest and reaches a speed of 12 m/s in 20 s. Its acceleration is

0.6 m/s^2 Work: (12-0)/20=0.6 (vf-vi/t=a)

A car whose mass is 1600 kg (including the driver) has a maximum acceleration of 1.2 m/s2. If three 80-kg passengers are also in the car, its maximum acceleration will be

1.04 m/s2

A 1-kg mass has a KE of 1 J when its speed is

1.4 m/s

A car whose initial speed is 40 m/s undergoes a constant acceleration of -5 m/s^2 when its brakes are applied. In the first 6 s after the brakes are applied, the car travels

150 m Work: 40(6)+.5 (-5) (6)^2=d d=vi (6) + .5 a6^2

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

The braking force needed to bring a 4000-kg truck to a stop from a speed of 20 m/s in 5 s is

16,000 N Work: a=20-0/5=4 --> F=4000(4) a=vf-vi/t F=ma

A ball is thrown upward with a speed of 30 m/s. It will continue to rise for about

3.1 s Work: h=30/9.8

A 60-kg woman climbs a mountain 2000 m high in 10 h. Her average power output during the climb is

33W Work: W=Fd F(or PE)=mgh PE=60(9.8) (2000)=1176000/t t=10h=36000s 1176000/36000s=32.6W

Arrange the following planets in the order of their distance from the sun. 1. Venus 2. Mars 3. Earth 4. Mercury

4, 1, 3, 2

A 1-N weight has a KE of 1 J when its speed is

4.4 m/s

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

45km

An airplane travels at constant speed for a distance of 120 km in a time of 15 min. Its speed is

480 km/in

An 800-kg car moving at 80 km/h overtakes a 1200-kg car moving at 40 km/h in the same direction. If the two cars stick together, the wreckage has an initial speed of

56 km/h

The weight of a 60-kg person is

588 N Work: 60 (2.20462)=132.2772 (4.45N) = 588N

The work done in lifting 30 kg of bricks to a height of 20 m on a building under construction is

5880 J Work: F=mgh F=30(9.8)(20)

A ball is thrown upward with a speed of 30 m/s. About how long after it was thrown will the ball reach the ground?

6.1s

The mass equivalent of 6.0 MJ is

6.7 × 10^-11 kg.

A sedentary person requires about 6 million J of energy per day. This rate of energy consumption is equivalent to about

70 W Work: P=e/t P=6M/86,400s=69.4W

A Planet not visible to the naked eye is

Neptune

In which one or more of the following is the earth assumed to be the center of the universe?

The Ptolemaic system.

Which of the following statements is true?

The moon is chiefly responsible for the tides, with the sun's influence modifying the tidal range.

Ball A is thrown horizontally and ball B is thrown upward.

They have the same downward acceleration.

The sun

attracts light waves passing nearby.

When the sun, the earth, and the moon are all in line

high tides are higher than usual and low tides are lower than usual.

According to the general theory of relativity, gravitation

is a distortion in space-time.

Which of the following is not a unit of work?

kilogram-meter

On a molecular level heat is

kinetic energy

Gravity is NOT

responsible for holding atoms and molecules together.

Kepler modified

the Copernican system.

Leap years are needed because

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

High tides occur

twice a day

In most parts of the world high tides occur approximately

twice a day

Rolling a ball up an inclined plank requires an amount of work proportional to the

height of the ball is raised

Astrology

is nonsense

The ongoing evolution of living things

is one of the basic concepts of biology.

What distinguishes the scientific method from other ways of looking at the natural world is

its reliance on experiment and observation.

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

law

Scientific theories

must be constantly reviewed to see whether they are in accord with new experimental observations.

On a rainy day the maximum frictional force between a car's tires and a certain level road surface is reduced to half its usual value. The maximum safe speed for rounding a curve is

reduced to 71% of its usual value.

A day is the time needed for

the earth to turn completely on its axis.

When the speed of a moving object is halved

the momentum is halved

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

the speed of light

A year is the time needed for

the sun to drift completely around the sky.

If the earth were to revolve on its axis slower than it does today, its shape

would be closer to a perfect sphere.

A total of 4900 J is expended in lifting a 50-kg mass. The mass is raised to a height of

10m Work: F=mgh 4900=50(9.8)h

A net horizontal force of 2000 N is applied to an 800-kg car at rest. The car's speed after 5 s will be

12.5 m/s Work: 2000=800a --> a=2.5 2.5=vf-0/5 --> vf=12.5 F=ma a=(vf-vi)/t

A 1-kg object is moving at 10 m/s. To double its kinetic energy, its speed should be increased to approximately

14 m/s

A mast is 60 ft tall. The SI equivalent of this height is

18.3m

A 430-g soccer ball lying on the ground is kicked with a force of 800 N. If the kick lasts 0.01 s, the ball flies off with a speed of

18.6 m/s

A car starts from rest with a constant acceleration of 3 m/s2. In the first 4 s the car travels

18m

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

196 W

The work you do in raising an orange from your waist to your mouth is roughly

1J

After a stone dropped from a cliff has fallen 20 m, the stone's speed is approximately

20 m/s Work: v=d/t v=20/1s

In bright sunlight, a solar cell with an efficiency of 20% might have a power output per square meter of

200W

Which of the following statements is incorrect?

All scalar quantities have directions

A constellation is

An apparent pattern in the sky

The shortest of the following units is the

Centimeter

When first proposed, a scientific idea is usually called a

Hypothesis

A week is the time needed for

None of these choices are correct

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

Remains the same

In the distant past, the length of the day was

Shorter than 24 hours

The acceleration of gravity on the surface of Mars is 3.7 m/s2. Compared with his or her mass and weight on Earth, an astronaut on Mars has

The same mass and less weight

Stars and planets are round because

gravity forces them into this shape.

A stone is thrown upward from a roof at the same time as another, identical stone is dropped from there. The two stones

have the same acceleration when they reach the ground

To prevent it from tumbling in flight, a projectile such as a football is sent off spinning. The physical principle involved is

conservation of angular momentum.

The time needed for a planet to orbit the sun

depends on the average distance of the planet from the sun.

The time at which a given star rises above the horizon each night is

earlier than the night before.