Mastering Physics 2 chapter 4,5,6,7
how many joules is needed to change the temperature of 1 gram of water by 1°C?
4.19 J
at what temperatures do the combines effects of contraction and expansion produce the smallest volume of liquid water
4°C
what is the magnitude of gravitational force between two 1-kg bodies that are 1m apart?
6.67 x 10^-11 N
what is the magnitude of the gravitational force between earth and a 1-kg body at its surface?
9.8N
use Q=cm🔼T to find how many joules it takes to raise the temp of 0.40 kg of water from 20 to 26°C. for the specific heat capacity use 4190 J/kg. °C
Q= 1.0 x 10^-4 J
Q= cm🔼T. use the formula to find how many cal it takes to raise the temp of 240g of water from 20 to 25°C. for the specific heat capacity,c. use 1 cal/g. °C.
Q=1200 cal
Why is one able to walk on red hot coals without getting ones feet burned
The coals are not good conductors of heat
How does the pressure exerted by bubbles in the water compare with the atmosphere pressure when the temperature of water in an open pressure cooker is below 100C and when it equals 100C?
The pressure exerted by the bubbles is less than the atmosphere pressure below 100C and equals the atmospheric pressure at 100C
a projectile is launched upward at an angle of 75° from the horizontal and strikes the ground a certain distance down range. for what other angle of launch at the same speed would this projector land just as far away?
15°
What do you use a pressure cooker for
To prevent boiling and cooling
is the temperature of an object a measure of the total translational kinetic energy of molecules in the object or a measure of the average translational kinetic energy per molecule in the object?
average translational kinetic energy per molecule
as entropy is a system increases, energy in the system _______
becomes less ordered
the moon falls toward earth in the sense that it falls
beneath the straight line path it would take without gravity
why does the strip behave as it does when dr hewitt heats it up?
both metals expand unequally.
when a satellite travels at constant speed, it's shape is an____
circle
a satellite in elliptical orbit about earth travels fastest when it moves_____
close to earth
the second law of thermodynamics tells us that heat flows from_____
cold to hot with work input
which of the following is thought to be more prevalent in the universe; ordinary matter, dark matter, or dark energy?
dark energy.
what is the state of pluto in the family of planets?
dwarf planet.
the amount of heat transferred to a system can be measured in______
either calories or joules
thé rock bottom coldest an object can hope to reach is____
either of these answers. (absolute zero, -273°C)
at what part of an alliptical orbit does an earth satellite have the greatest speed? the least speed?
greatest, when closest. least, when furthest.
how does heat differ from thermal energy
heat is thermal energy in motion
what is the reason for ice being less dense than water?
ice crystallizes with an open structure
under what condition is your weight equal to mg?
if you stand in equilibrium on a surface and drop an object that free falls at G due to gravity or the acceleration of the surface or a combination of both your weight is mg
when disorder in a system increases does entropy increase or decrease
increase
what happens if dr hewitt heats up the strip?
it bends
what can become of heat that is added to a system but doesn't increase the temperature of the system?
it can go bro changing the systems state. it can do external work.
in what sense does the moon "fall"
it falls away from the straight line it would follow if there were no force on it.
what happens to an object close to earths surface of it is given a speed exceeding 11.2 km/s
it has espace velocity and moves away from the earth never returning. it then enters an orbit about the sun.
how does the force of gravity between 2 bodies change when the distance between them is tripled?
it is 1/9 of the initial force.
Which of the following would best describe the conductive properties of wood?
it is a good insulator
a stone is thrown upward at an angle. neglecting air resistance, what happens to the horizontal component of its velocity along its trajectory?
it is constant.
microscopic slush in water tends to make the water___
less dense
hot sand cools off faster than do plants and vegetation. hence the specific heat capacity for sand is________
less than that of plants and vegetation
when a projectile achieves espace speed from earth, it _____
outruns the influence of earths gravity but is never beyond it.
the perturbations of uranus led to what greater discovery?
pluto
which law is thermodynamics is related to the direction of heat transfer
second law
which warms faster when heat is applied; iron or silver which has the lowest specific heat capacity?
silver. silver.
when an astronaut in orbit is weightless he or she is ______
still in grips of earths gravity
what role does temperature have in the direction of thermal energy flow?
temperature differences specify the direction of heat flow from hot to cold.
state newtons law of universal gravitation in words. then express it in one equation.
two bodies attract each other woth a force directly proportional to the product of their masses and inversely proportional to the square of the distance between them. F~m1m2/d^2
why does a bimetallic ship bend with changes in temperature
two different metal plates bonded to each other have different expansions as temperature changes
would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that moved upward at a constant velocity? what about in an elevator that moved downward at a constant velocity?
up: no change. down: no change.
would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that accelerated upward? accelerated downward?
upward; more compressed. downward; less compressed.
temperature is generally proportional to a substances _____
average translational kinetic energy of its particles
a projectile is launched vertically at 100 m/s. if air resistance can be neglected, at what speed does it return to its initial level?
100 m/s.
by how much does the pressure of a gas in a rigid vessel decrease when the temperature is decreased from 0°C to -1°C?
1/273
F= G m1m2// d^2 calculate the force of gravity between a newborn baby mass of 3.5 kg and the obstetrician mass of 110kg. who is 0.46 m away from the baby.
F= 1.2 x 10^-7 N
F=G m1m2//d^2 form the force of gravity between earth (mass= 6 x 10^24 kg) and the moon (mass= 7.4 x 10^22 kg) the average earth moon distance is 3.8 x 10^8 m.
F= 2.1 x 10^20 N
which exerts a gravitational force on the baby. mars (mass=6.4 x 10^23 kg, distance= 5.6 x 10^10) or the obstetrician ? the obstetrician. by how much?
Fobs/Fmars= 2.5
what name is given to "thermal energy in transit"
Heat
How does using a pressure cooker affect the amount of internal energy in the water inside the pressure cooker and why
It increases the amount of internal energy because it does not allow the heat to boil the water.
What happens to the conductive properties of wood when it gets very hot
It will continue to remain a good insulator
How would you walk on red hot coals without getting your feet burned
Walk fast
distinguish between a calorie a Calorie and a joule.
a calorie is the energy needed to warm 1g of water by 1°C. a Calorie is 1000 calories. a calorie is 4.19 joules
of a satellite were beyond earths gravity what path would it follow?
a straight line
what kind of strips is dr hewitt holding in his hand?
a strip consisting of brass on one side and steel on the other, welded together.... a bimetallic strip
under what condition does a thermometer measure the temperature of its surroundings? why do we say that "a thermometer measures its own temperature "
a thermometer measures the temperature of its surroundings when the it has reached equilibrium at the temperature of its surroundings
to say that water has a high specific heat capacity means that water ___
absorbs a lot of energy for a small increase in temperature.........releases a lot of energy in cooling.......requires a lot of energy in order to increase in temperature.
earth is gravitationally pulled toward______
all of the above. (jupiter, mars, the sun)
when the temperature of a strip of iron is increased, the length of the strip____
also increases.
a storm is thrown upward at an angle. neglecting air resistance, what happens to the vertical component of its velocity along its trajectory?
at first it slows down, then reversed direction and speeds up
where do you weigh more- sea level or atop one of the peaks of the rocky mountains?
at sea level because your distance to the center of the earth is at least at sea level.
newton did not discover gravity, for early humans discovered that whenever they fell. What newton did discover is that gravity______
extends through the universe
which law of thermodynamics consists of the conservation of energy applied or thermal systems
first law
cute a way in which the energy value of foods is determined
food is burned
what are the temperatures for freezing water on the delicious and the fahrenheit scales, respectively? for boiling water?
freezing water 0°C,32°F. boiling: 100°C,212°F
what are the temperatures for freezing water and boiling water on the kelvin scale?
freezing: 273 K. boiling: 373 K
why is it important that a satellite remain above earths atmosphere?
friction with the air will exert forces on the satellite slowing it down.
in which direction does thermal energy spontaneously flow between hot and cold objects?
from hot to cold
what was the cause of perturbations discovered in the orbit of planet uranus?
gravitational pulls from neptune
which of the following generally expands more for an equal increase in temperature. solids or liquids?
liquids.
is the period longer or shorter for orbits of greater altitude?
longer
when you toss a projectile sideways it curves as it falls. it will be an earth satellite if the curve it makes ________
matches the curved surface of the earth
when the temperature of ice cold water is increased slightly does it undergo a met expansion or a net contraction
net contraction
a dropped ball accelerated as it falls. but a ball rolling on a horizontal surface has zero acceleration because_____
no horizontal force acts on it.
a space vehicle can outrun earths gravity, but can it get entirely beyond earths gravity?
no. earths gravity extends to infinity, decreasing the inverse square of the distance.
when a satellite is above earths atmosphere, is it also beyond the pull of earths gravity? defend your answer.
no. gravity is an inverse square law force and extends to infinite distance.
suppose that we replace the aluminum with a mystery metal and repeat the experiment in the video. as in the video, the mass of the metal is the same as that of the water. room temperature is about 20°C before the start of the experiment. the water heats up to 40°C and the mystery metal heats up to 80°C. compared to that of water, the heat capacity of our mystery metal is_______
one third as great. 1/3.
consider a space probe three times as far from earths center as it would be at earths surface. compared to at earths surface it's gravitational attraction to earth at this distance is about _____
one- nineth as much.
which law of thermodynamics is related to a system reaching 0 K?
third
why does the force of gravity change the speed of a satellite in an elliptical orbit?
the force of gravity has a component parallel to the velocity of the satellite
what is the relationship between waters high specific heat capacity and europe's climate
the gulf stream carries warm water to the coast of europe where winds blow water warmed air over europe keeping winters mild
why is heat measured in joules
the international metric system specified that heat should be measured in joules
which exerts a gravitational force on the baby. mars (mass=6.4 x 10^23 kg, distance= 5.6 x 10^10) or the obstetrician ?
the obstetrician.
what did newton discover about gravity
the same laws of gravity apply on the earth and in the heavens.
what connection does earths curvature have with the speed needed for a projectile to orbit earth?
the speed has to be great enough that the distance the projectile falls each second matches the earths curvature.
why doesn't the force of gravity change the speed of a bowling ball as it fills along a bowling lane?
there is no component of the force in the direction of motion of the ball.
why doesn't the force of gravity change the speed of a satellite in circular orbit?
there is no component of the force in the direction of motion of the satellite
explain why occupants of the international space station are firmly in the grip of earths gravity even though they have no weight.
there is no support force in free fall so they are weightless, but earths gravity still pulls on them and accelerates them
does a hot object contain a thermal energy or does it contain heat?
thermal energy
heat is simply another word for_____
thermal energy that flows from hot to cold.
recall that the water balloon did not pop because most of the candles thermal energy went into heating the water. let's think about the process in detail. the high heat capacity of water means that the water in the balloon warmed only slowly. contact with this relatively cool water kept the balloons thin rubber skin from getting hot to melt. rubber conducts heat slower than water. if u make the rubber skin thicker wi the skin be more or less likely to melt? think about the conduction of heat across the skin between the hot side facing the candle and the cooler side in contact with water. what change will make the balloon more likely to pop? __________
use a thicker balloon......use a liquid that has a LOWER heat capacity than water.
how does the specific heat capacity of water compare with the specific heat capacities of other common materials?
water and a higher specific heat capacity than other common materials
under what condition can the entropy of a system be decreased
when work is done on the system
when can thermal energy in a system move from lower to higher temperatures
when work is done on the system
If you are able to grab a hot pan and pull it out by the handle without burning yourself, what kind of handle must the pan have and why
wood handle because it's a better insulator
how much energy can be removed from a system at 0 K?
zero energy
what pressure would you expect in a rigid container of 0°C gas cooled to -273°C?
zero pressure