Properties of Matter

Question 1

what are the features of kinetic molecular model?
unit of Young modulus?

Answer 1

1. matter is made up of particles called molecules.
2. the molecules remain in continuous motion.
3. molecules attract each other.
   N/m2

Question 2

properties of solids and liquids and gases?

Answer 2

pg 164

Question 3

why liquids and gases are called fluids?
Hg is _________ times denser than water.

Answer 3

because they don’t have fixed shape & has the ability to flow.
13.6

Question 4

how is plasma formed? where is it found? is it a good conductor?

Answer 4

4th state of matter in which gas occurs in its ionic state, (loses e to from +ve ion due to strong collisions b/w molecules due to heat)
neon & fluorscent tube sun
yes highly

by heating gas

Question 5

define density? unit? symbol? formula? what is required to find density of object? mass=?
volume=?

Answer 5

mass per unit volume.
kg/m3
rho, ρ
mass/volume
mass & volume
p x v
m/p

Question 6

1 m3 = ________ litre
1 litre= ________ m3
1 m2= __________ cm2

1cm3= ___________ m3
1g/cm3 = ________ kg/m3
1cm2 = ____________ m2
convert 4.7 g/cm3 to kg/m3

Answer 6

1000 litre
10-3
1000
10-6
1000 kg/m3
10-4 (divide by 10,000)
multiply by 1000

Question 7

define pressure? unit? symbol? formula? what is required to find pressure? quantity?

Answer 7

force per unit area.
N/m2 (Pascal Pa)
P
P=F/A
force and area
scalar

Question 8

density ______ as we go up.
The relation between density and temperature is ________________.
The relation between pressure and density is ____________.

Answer 8

decreases
inversely proportional
direct

less temperature less K.E so tightly packed so more density

less pressure less air molecule so less mass so less density

Question 9

Nm-2 is same as ________.
what is barometer?
what is atmospheric pressure at sea level?

Answer 9

pascal (F/A)
the instrument that measures atmospheric pressure.
1.013 x 10⁵ / 101,300 Pa

Question 10

1 atm=
1 bar=
is atmospheric pressure downward or upward?

Answer 10

1.013 x 10⁵ / 101,300 Pa
1.000 x 10⁵ Pa / 100,000 Pa
1.013 x 10⁵ / 101,300 Pa or 1 atm
downward exerted by the weight of the air over our heads.

bar: pressure unit used in weather maps.
mbar milibar: 100 Pa

Question 11

how mercury barometer helps us to measure atmospheric pressure?

Answer 11

when the tube filled w/ Hg is inverted into a flat dish containing Hg, it doesn’t empty into the bowl completely.
Atm exerts a P on the surface of mercury, this atm pushes the mercury in the tube to some h which is 760 mm at sea level.

if it’s at sea level then 760 mm Hg = 1 atm

Question 12

atmospheric pressure is _____________ proportional to temperature.
atmospheric pressure is _____________ proportional to increasing altitude.

Answer 12

inversely
inversely

increase temp. = decrease in atm
increase in altitude = decrease in atm

more temp. more K.E, more expansion, less density, less molecule exerting downward pressure, atm decrease.
as u go up, less air above you, so less mass, so less atm

Question 13

why atmospheric pressure rises on a cold night?

Answer 13

less temp. air cools down, K.E decreases, condensed, more density, more molecules exerting downward pressure, atm increase

Question 14

drop in atmospheric pressure in a place means ____________?

Answer 14

windy, rainy, breeze
sudden fall = storm, rain, typhoon

minor but rapid fall

Question 15

range of atmospheric pressure in mbar?
strength of wind is determined by _________.

Answer 15

from very high pressure of 1,040 mbars to as low as 950 mbar.
pressure difference.
winds move from high pressure regions to low pressure regions.

Question 16

pressure in a liquid varies in __________.
formula for liquid pressure. what does this show? unit?

Answer 16

increase w/ depth
P= ρ x g x h
pressure at a depth h in a liquid of density ρ.
Pascal N/m2 same as pressure

Question 17

derive fluid pressure formula?

Answer 17

pg 151

Question 18

state pascal’s law

Answer 18

an external pressure applied to an enclosed fluid is transmitted unchanged in magnitude to every point of the fluid.

for both gases and liquids

Question 19

explain the braking system in vehicles?

Question 20

why objects feel light under water?
what does buoyant force depend on?
state archimedes law?
formula for buoyant force?
when will an object sink and rise?

Answer 20

1. due to buoyancy, opposing the force of gravity & making the weight of the object in water less than its actual weight in air.
2. the weight of the liquid displaced.
3. when an object is totally or partially immersed in a liquid, an upthrust acts on it equal to the weight of the liquid it displaces
4. pgV
5. If the buoyant force is greater than object’s weight= rise If the buoyant force is less than object’s weight= sink If the buoyant force is equal to object’s weight= suspended.
   for that it should have less density than water.

m f= mass of fluid (liquid)

Fb= buoyant force

an upward force exerted by the water
buoyant force is always present , rise sink suspended

Question 21

how to find density of an object in terms of archimedes principle? what do we need to know to find that?
what is the density of water?
state principle of flotation?

Answer 21

pg 157
weight of the solid in air
weight of the solid in liquid
1000kg/m3
a floating object displaces a fluid having weight equal to the weight of the object.

in other words weight of displaced fluid= weight of the object

Question 22

an object floats if it ______
If the buoyant force is less than the weight of the object, the object will ______.

Answer 22

its weight is equal or less than than the upthrust.
or
it displaces an amount of liquid, greater than or equal to the weight of the body.
sink

cz more displaced liquid = more buoyant force= so displaced liquid should be greater or equal to the weight of the body.
if its greater will accelerate to be equal to the weight

Question 23

what is deforming force?
what is elasticity?
define elastic limit?
what is inelastic?

Answer 23

1. force that changes shape, length or volume of an object.
2. the ability of a deformed body to return to original shape & size when the deforming force is removed.
3. the limit at which most materials are elastic.
4. materials that don’t return to their original shapes after being distorted.

beyond elastic limit, an elastic material won’t return to its origiinal shape.

Question 24

state Hooke’s law.
its formula
what does minus show?
what is force/spring constant? its unit

Answer 24

the strain of the material is proportional to the applied stress within the elastic limit of that material.
F= -k x
force is against displacement
constant to show how many newtons to stretch an object by 1 m.
N/m k

Question 25

what is stress? formula? unit?

Answer 25

force applied within elastic limit per unit area of cross-section of elastic material to produce deformation.
stress= force/ area
N/m2 or pascal

it is a force related to producing deformation

Question 26

what is strain? its unit? formula? what is tensile strain?

Answer 26

the extension produces per unit length of a material under stress.
it’s a ratio, so no unit
strain= extension/ original length
= x / l
if stress produces a change in the length of an object, then the stress is tensile stress.

extension= change in length

Question 27

define young’s modulus? formula? derivation? unit? symbol? what does it depend on?

Answer 27

the ratio of stree to tensile strain
Y= stress/strain = F X l/ A X x
N/m2
Y
material of the wire

within elastic limit, the strain produced in a stressed wire or ratio is constant. (Y)

Question 28

how to convert cm2 to m2
mm2 to m2?
mm to m?

Answer 28

divide by 10,000
divide by 1000 x 1000
divide by 1000

Question 29

find volume of solid when immersed in liquid when weights are not given for principle of flotation formula?
density of water?
g/cm3 to kg/m3?
kg/m3 to g/cm3?

Answer 29

v=m/d
mass of solid= given
density of liquid (cz the medium is liquid if the solid was in air it would be denisty of air)= given
1000kg/m3
1g/m3
multiply by 1000
divide by 1000

reference = 7.10