physics 203.01

a meter is not equal to

.01 km

The longest of the following is

0.00001 km.

Mars is about 1.5 times as far from the sun as the earth and its mass is about 0.1 times the earth's mass. Relative to the gravitational force the sun exerts on the earth, the force it exerts on Mars is about

0.044 as much.

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

0.2 m/s^2

a weightlifter raises a 200-kg barbell through a height of 2 m in 2.2s. The avgrgae power he developes during the lift is

1.78 kW

a total of 4900 J is expeneded in lifting a 50- kg mass. teh mass is raised to a height of

10 m

The proportion of the world's electricity that comes from nuclear energy is roughly

10%

In 6 min a person running at 10 km/h covers a distance of

1000m

A horizontal force is applied to a 2-kg ball on a smooth table. The ball's speed is 8 m/s when it has gone 4 m. The magnitude of the force is

16 N

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 moive through the water?

17ft/s

In the first 3 s after a car starts from rest with an acceleration of 4 m/s2it will travel

18m

A force of 2 N acts on a 2-kg object, initially at rest, for 2 s. During that time the object moves a distance of

2 m

The size of a picture is given as 84 cm by 255 cm. Since (84)(255) = 2.142 exactly, the area of the picture is expressed with the correct number of significant figures as

2.1 m^2

In a good wind, a modern large wind turbine might have a power output of

2000 kW

the linear momentum of a 400-kg giraffe gallaping at a 5 m/s is

2000 kgm/s

The minimum number of unequal forces whose vector sum can equal zero is

3

A moose weighing 3 kN is standing still. The force the ground exerts on the moose is

3 kN

Arrange these fuels in increasing order of energy given off per gram when they are burned. 1. gasoline 2. hydrogen 3. coal 4. ethanol

4. ethanol 3. coal 1. gasoline 2. hydrogen

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

4. mercury 1. venus 3. earth 2. mars

A stone dropped from a cliff reaches the ground in 4 s. The stone's speed is then

40 m/s

When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2. How far does the car travel before it comes to a stop?

42m

a 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

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

6 kg

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

70 W

A man whose mass is 80 kg on the earth's surface is in a spacecraft at a height of 2 earth radii above the earth's surface. His weight there is

87 N

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

Galileo

A week is the time needed for

None of the choices are correct

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 of A^2 + B

eventually, if bioethanol remains in use, it will probably be made from

cellulose

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 then the night before

n the United States, bioethanol from corn is added to gasoline for vehicle fuel because

govermnet action favors its production and use

the earths atmosphere is mainly heated by

infrared light radiated by the earth

A car whose speed is a steady 50 km/h

is accelertaed when it clibs a hill, goes over the crest, and descends on the other side

The escape speed needed for an object to leave the earth permanently

is more than the minimum speed it needs to become an earth satellite.

what distguishes the scientific method from otehr ways of looking at the natural world is

its reliance on experiment and observation

An onject that has linear momentum must also have

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

n the United States, the lowest cost per unit of electrical output in the immediate future would come from using which of these energy sources?

natural gas

fuel cells

need continuous supplies of fuel

the period of the earths orbit around the sun is

one year

a moving object does not necessarily have

potential energy

a rocket is fired in sapce. as it moves, the total momentum of the rocket and its exhaust gases

remain the same

in the distant past, the length of the day way

shorter than 24h

the lengtgh of the year is

slightly more than 365 days

which of the following statements is not true?

the US has less then 5% of the worlds coal reserves

Keepler modified

the copernican system

a day is the time needed for

the earth to completely turn on it axis

solar radiation is ultimately responsible for

wind energy