Natural Science

500 N

What is the force of gravity on a 500-N woman standing on earths surface?

a. decreases

a rock is thrown upward at 50 degrees with respect to the horizontal. as it rises, its vertical component of velocity

e. none of the above

a satellite is an elliptical orbit travels at constant

b. low specifc heat capacity

a substance that heats up relatively quickly has a

black pot

cold water will warm to room temperature faster in a

e. none of the above

consider two planets in space that gravitationally attract each other. if the masses of both planets is doubled and the distance between them is doubled then the force between them is

c. both a and b (production + consumption)

heating earths atompshere is caused by energy

b. is made of open structured hexagonal crystals

ice has a lower density than water because ice

b. 2s

if a projectile is fired straight up at a speed of 10m.s the total time to return to its starting position is about

cools

if a volume of air is warmed it expands. if a volume of air expands it

a. considerably colder

if air were a better conductor than it is at nighttime the earth would be

true

it is possible to totally convert a given amount of mechanical energy into heat

b. that gravity is universal

newton discovered

absorb radiation relatively well

objects that radiate relatively well

b. their tangential velocities

planets would crash into the sun if it weren't for

c. remains constant

roll a bowling ball off the edge of a table. as it falls, its horizontal component of motion

high specific heat capacities

some molecules are able to absorb large amounts of energy in the form of internal vibrations and rotations. materials composed of such molecules have

a. almost as much as the shuttles weight on earths surface

the amount of gravitational force that acts on the space shuttle while in orbit is

a. in the same direction of gravitational attraction

the direction of a gravitational field

d. its orbital period is about 24 hours

the earlybird communication satellite hovers over the same point on earths equator indefinitelty. this is because

b. practically the same weight

the force of gravity acts on all apples on an apple tree. some apples are twice as far from the ground as others. these twice as high apples for the same mass have

d. 141 km/h

the ground speed of an airplane that has an airspeed of 100 km/h when it is in a 100kn-h crosswind is

b. shorter the wavelengths it radiates

the higher the temperature of an object is

a. jupiters radius is 10 times earth radius

the planet Jupiter is about 300 times as massive as Earth, yet on its surface you would weigh only about 3 times as much. this is because

abosorber of radiant energy

the pupil of your eye is a net

a. has a higher temperature than the earth

the reason the suns radiant energy is of shroter wavelengths than the earths is because the sun

c. both the same

two motorcycle stunt drivers, one light and the other much heavier, drive their motorcycle up and off an inclined ramp at identical speeds. they both rise in the air and land downrange. neglecting air drag, the one to attain the greatest height and greatest range is the

c. increases

two objects move toward each other because of gravity. as the objects get closer and closer the acceleration of each

c. both a and b(thermal energy and temperature)

when mechanical work is done on a system there can be an increase in its

a. one third from the base

where is the center og gravity in a triangle

c. both forces are the same

a very massive object A and a less massive object B move toward each other under the influence of gravitation. Which force if either is greater?

a. 273 degrees C

a volume of air has a temperature of 0 degrees. an equal volume of air that is twice as hot a temperature of

b. like the shuttle, pulled by Earths gravitation

a weightless astronaut is an orbiting shuttle is

high specific heat capacity

the moderate temperature of islands throughout the world has much to do with waters

c. 5m below the straight line

throw an object at an angle upward. with no gravity it will follow a straight line path. But because of gravity at the end of 1s it is

b. supports this common knowdlege

it is commonly thought that a can of beverage will cool faster in the coldest part of a refrigerator

b. at or about 30 degrees C

pour a liter of water at 40 degrees C into a liter of water at 20 degrees c and the final temperature of the two becomes

right away

suppose you are served coffee at a reastaraunt before you are ready to drink. in order for it be the hottest when you are ready for it, you should add cream

both a and b ( density & pressure)

warm air rises because faster moving molecules tend to move to regions of less

a. center seeking

what does centripetal mean?

d. the speed required to leave a gravitational field

what is escape speed?

c. copper expands more than iron

when a bimetallic bar made of copper and iron strips is heated, the bar bends towrd the iron strip. the reason for this is,

b. vast number of open spaces in the hexagonal ice crystals

when ice floats in water a small part of it extends above the surface. interestingly enough the volume of ice that extends above the surface is equal to the volume of the

water at 4 degrees c

which of the following expands most when the temperature is lowered? equal volumes of

c. iron

which of the following normally warms up faster when heat is applied

a. little girl wearing heavy boots

who could lean the farthest over a cliff without falling?

Earth

An object is placed exactly halfway between earth and moon. The object will fall toward the

c. fluids

energy transfers by convection is primarily restricted to

second law of thermodynamics

entropy is closely related to the

c. always false

for the astronauts inside the orbiting space shuttle there is no force of earths gravity acting on them. this statement is

b. 1/4 m/s

Consider an escalator at an angle of 45 degrees above the horizontal that moves with a velocity of 2.0 m/s. the vertical component of its velocity is about

b. less the gravitational force between them

according to Newton, the greater the distance between masses of interacting objects the

a. greater the gravitational force between them

according to newton the greater the masses of interacting objects the

b. the same as It was at the top of its path

after a rock that is thrown straight up reaches the top of its path and is starting to fall back down, its acceleration is (neglect air resistance)

B. nearest earth

an earth satellite is in an elliptical orbit. the satellite travels fastest when it is

true

an earth satellite is simply a projectile freely falling around the earth

b. longer than the ascent time

an object is thrown vertically into the air. Because of air resistance, the time for its descent will be

d. moving

atoms and molecules are always

orbiting earth with a 24-hr period

communications and weather satellites always appear at the same place in the sky. this is because these satellites

two of the above

consider a closed, sealed can of air place on a hot stove. the container air undergoes an increase in

293

consider a piece of metasl that is at 10 degrees c. it is heated until it has twice the thermal energy its temperature will be

a. black pot

hot water will cool to room temperature faster in a n

a. less than 8km/s

minimal orbit speed about earth is about 8 km/s. mimimal orbital speed about the moon would be

131.5 degrees c

on a chilly 10 degrees C day , your firend who likes cold weather wishes it were twice as cold. taken literally this temperature would be

a. without support forces

passengers in a high flying jumbo jet feel their normal weight in flight, while passengers in the orbiting space shuttle do not. this is because passengers in the space shuttle are

less than 30 degrees C

place a 1-kg block of iron at 40 degrees in a kilogram of a water at 20 degrees c and the final temperature of the two becomes

b. 30 degrees

two projections are fired at equal speeds but different angles. one is fired at an angle of 30 and the other 60 degrees. neglecting air resistance the projectile to hit the ground first will be the one fired at

c. 45m

a ball is thrown horizontally from the top of a tall cliff. three seconds later the ball has fallen a vertical distance of

0.5s

a bullet fired horizontally hits the ground in 0.5s. it had been fired with twice the speed in the same direction, it would have his the ground in

c. 600m

a bullet is fired horizontally within an intial velocity of 300m.s from a tower that is 20m high, if air resistance is negligible the horizontal distance the bullet travels before hitting the ground is

c. 100 m downrange

a gun with a muzzle velocity of 100 m/s is fired horizontally from a tower. neglecting air resitance where will the bullet be a 1s later?

b. the fired one

a hunter aims a rifle at an angle of 10 below the horizontal. the hunter fires a bullet while simultaneously dropping another bullet from the level of the rifle. which bullet will hit the ground first?

a. rise and fall back to earths surface

a projectie is fired vertically from the surface of earth at 10km/s. the projectile will

c. 75 degrees

a projectile is launched at an angle of 15 degrees above the horizontal and lands downrange. what other projection able for the same speed would produce the same downrange distance.

c. remains unchanged

a rock is thrown upward at 50 degrees with respect to the horizontal. as it rises its horizontal component of veloctiy

c. 5m

a stone is thrown horizontally from the top of a cliff. one second after it has left your hand its vertical distance below the cliff is

d. forget it you cant travel far enough

how far must one travel to get away from Earths gravitational field

c. decrease to one half your original weight

if earths mass decreased to one half of its original mass with no change in radius, then your weight would

b. decreases

if glass expanded more than mercury then the column of mercury in a mercury thermometer would rise when the temperature

b. more likely to freeze

if the specific heat capacity of water were lower than it is. ponds in the cold of winter would be

an igloo

if you were caught in freezing weather with only a candle for heat, you would be warmer in

b. quadruple

if your mass, the mass of earth and the mass of everything in the solar system were twice as much as it is now. yet everything stayed the same size your weight on earth would

d. 24.0 m/s

ignoring air drag what is the maximum speed that can be given to a horizontally moving tennis ball as it clears the net 1.25 m high to remain within the edge of the court which is 12.0 m distant

thermal equilibrium

the fact that a thermometer " takes its own temperature" illustrates

zero

the number of electrons delivered daily to an average American home by an average power utility in the mid 1980-s

b. radial distance

the period of satellite, the time it takes for a complete revolution depends on the satellites

b. radiation

the silver coating on the glass surfaces of a thermos bottle reduces energy that is transferred by

a. exactly 4 degrees C

the temperature at the bottom of Lake Tahoe high in the Sierra Mountian in California at this moment iis