Matric Part 1/9th Class Physics Chapter 7 Long Question With Answer for Unit 7 Properties of Matter

Question # 1

Q no: 7 (A) Explain hydraulic press, on what principle does it work.

Ans 1: Data :
F= 20N
L= 10mm
= 10 x 10^-3m
A= L x L = 10 x 10^-3x 10 x 10^-3
= 100 x 10^-6
= 1 x 10^-4m²
p=?
Solution:
As we know that
P = F/A
P= 20/1 x 10^-4
P= 20 x 10⁴
P= 2 x 10⁵Nm^-2 Ans

Question # 2

Q no 6B) Thedensity of air is 1.3 Find the mass of air in measuring 8m x 5m x 4m.

Ans 1: Data:
= 1.3
v= 8m x 5m x 4m
= 160m³
m = ?
Solution:
As we know that
Density = Mass/Volume
Mass = Density x Volume
=1.3 x 160
m = 208kg Ans

Question # 3

What is the principle of floatation. explain

Ans 1: Principle of floatation: a floating object displaces a fluid having weight equal to the weight of the object.
Example: an object sinks if its weight is greater than the upthrust acting on it. An object floats if its weight is equal or less than upthrust . When an object floats in a fluid, the upthrust acting on it is equal to the weight of object. In case of floating object, the object equal to the weight of the fluid displaced by the object. This is the principle of floatation. It is applicable on liquid as well as gases.
Ans 2: Applications: the applications of principle of floatation are following
Wooden block: a wooden block floats on water. it is because the weight of an equal volume of water is greater than the weight of the block. According to the principle of flotation. a body floats if it displaces the water equal to the weight of the body when it is partially or completely immersed in water.
Ans 3: Ships and boats: ships and boats are designed on the same principle of flotation. They carry passenger's and goods over water. It would sink in water if its weight including the weight of its passengers s and goods becomes greater than the upthrust of water.

Question # 4

What is density? explain

Ans 1: Density; density of a substance is defined as its mass per unit volume
Unit: its S.I unit is kilogram per cubic meter (kgm^-3)
Ans 2: Explanation; if we take equal volume of iron and wood, then we can easily declare that iron is heavier than wood. it means that density of iron is heavier than wood

Question # 5

What is barometer? how atmospheric pressure is measured using a barometer

Ans 1: Barometer; the instrument that measure atmospheric pressure is called barometer.
Ans 2: Construction of barometer; one of the simplest barometer is mercury barometer . It consists of a glass tube 1 m long closed at one end. It is filled with mercury
Ans 3: measurement of atmospheric pressure using a barometer : to measure atmospheric pressure, then after filing with mercury, barometer is invented in a mercury trough. Mercury in the tube descends and stops at a certain height. The column of mercury held in tube exerts pressure at its base. At sea level the height of mercury column above the mercury in the trough is found to be about 76 cm . Pressure exerted by 76 cm of mercury column is nearly 101300Nm-2 , equal to atmospheric pressure . It is common to express atmospheric pressure in term of height of mercury column. As the atmospheric pressure at a place does not remains constant, hence the height of mercury column also varies with atmospheric pressure .

Question # 6

Explain the variation in atmospheric pressure

Ans 1: Variation in atmospheric pressure : the atmospheric pressure decrease as we go up. The atmospheric pressure on mountain's is lower than at sea level. At a height above 30km, the atmospheric pressure becomes only7mm of mercury which is approximately 1000pa. It would becomes zero at an attitude where there is no air. Nearly half of its mass is between sea level and 10km. up to 30 km from sea level contains about 99% of the mass of the atmosphere. Thus, we can determine the altitude of a place by knowing the atmospheric pressure at that place.
Atmospheric pressure may also indicate a change in the weather . On a hot day, air above the earth becomes hot and expands. This causes a fall of atmospheric pressure in that region. On the other hand, during cold chilly nights, air above the earth cool down. This causes an increase in atmospheric pressure.
The changes in atmospheric pressure at a certain place indicate the expected changes in the weather condition of the place . For example, a gradual and average drop in atmospheric pressure means a low pressure in neighboring locality. Minor but rapid fall in atmospheric pressure indicates a windy and showery condition in nearby region. A decrease in atmospheric pressure is accompanied by breeze and rain. Whereas a sudden fall in atmospheric pressure often followed by a storm, rain and typhoon to occur in few hour time.
On the other hand, an increasing atmospheric pressure with a decline later on predicts an intense weather conditions. A gradual large increase in the atmospheric pressure indicates a long spell of pleasant weather .condition. A rapid increase in atmospheric pressure means that it will soon be followed by a decrease in atmospheric pressure indicating poor weather ahead.

Question # 7

Q no: 7B) State Archimedes principle and prove it and derive equation of up thrust of liquid.

Ans 1: Archimedes Principle:
When is totally or partially immersed in a liquid, an up thrust act on it equal to the weight of the liquid it displaces.
Explanation:
Consider a solid cylinder of cross-sectional area A and height h immersed in a liquid. Let h1 and h2 be the depth of the top and bottom surfaces of the liquid.
Then
h2-h1= h
If P1 and p2 are the pressures at the depth h1 and h2 p is its density, then
P1= pgh2
P2= fgh2
Let the force F1 is exerted the cylinder top by the liquid due to pressure P1 and the force F2 is exerted at the bottom of the cylinder due to P2
So
F1=pgh1A
F2=pgh2A
F1 and F2 are acting on the opposite faces of the cylinder. Therefore, the net force F will be F2- F1 in the direction of F2
F2 - F1 = pgh2A -pgh1A
=pgA(h2-h1)
=pghA
= pgV

Question # 8

State and explain Pascals law

Ans 1: Pascals law: pressure applied at any point of a liquid enclosed in a container, is transmitted without loss to all other parts of liquid
Ans 2: Explanation: consider a glass vessel. By pushing the piston exert force on water . this pressure is transmitted equally throughout the liquids in all directions water comes out of holes in vessel with some force.
Ans 3: Note: Pascals law hold good of fluid, liquid's and gases

Question # 9

Q no 5 (B) How much would be the volume of ice formed by freezing 1 liter of water.

Ans 1: Data:
Volume of water = V₁= 1 liter Volume of ice on freezing=V₂= ?
Solution:
As we know that Volume of ice/Volume of water =density of water/density of ice
Volume of ice = density of water/density of ice x Volume of water
= 1000/920 x 1
= 109 liters Ans

Question # 10

State and explain Hook's law

Ans 1: Hook's law: the strain produced in a body by the stress applied to it is directly proportional to the stress with in the elastic limit of the body
Ans 2: Explanation; Hook's law is applicable to all kinds of deformation and all type of matter i.e. solids, liquids or gases within certain limit. This limit tells the maximum stress that can be safely applied on a body with out causing permanent deformation in its length volume or shape.
In other words, it is a limit with in which a body recovers its original length, volume or shape after the deforming force is removed. When a stress crosses this limit, called the elastic limit, a body is permanently deformed and is unable to restore its original state after the stress is removed

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Matric Part 1/9th Class Physics Chapter 7 Long Question With Answer for Unit 7 Properties of Matter

9th Class English Medium Subjects

9th Class Urdu Medium Subjects

Online Long Questions For Chapter 7 "9th Class Physics Chapter 7 Long Question Preparation "

Physics (New Book) - 9th Class Physics Chapter 7 Long Question Preparation

Q no: 7 (A) Explain hydraulic press, on what principle does it work.

Q no 6B) Thedensity of air is 1.3 Find the mass of air in measuring 8m x 5m x 4m.

What is the principle of floatation. explain

What is density? explain

What is barometer? how atmospheric pressure is measured using a barometer

Explain the variation in atmospheric pressure

Q no: 7B) State Archimedes principle and prove it and derive equation of up thrust of liquid.

State and explain Pascals law

Q no 5 (B) How much would be the volume of ice formed by freezing 1 liter of water.

State and explain Hook's law

Prepare Complete Set Wise Questions For Chapter 7 "9th Class Physics Chapter 7 Long Question Preparation "

Set 1

Set 2

9th Class Physics Chapter 7 Long Question Preparation - Set 1

Q no: 7 (A) Explain hydraulic press, on what principle does it work.

Q no 6B) Thedensity of air is 1.3 Find the mass of air in measuring 8m x 5m x 4m.

What is the principle of floatation. explain

What is density? explain

What is barometer? how atmospheric pressure is measured using a barometer

Explain the variation in atmospheric pressure

Q no: 7B) State Archimedes principle and prove it and derive equation of up thrust of liquid.

State and explain Pascals law

Q no 5 (B) How much would be the volume of ice formed by freezing 1 liter of water.

State and explain Hook's law

9th Class Physics Chapter 7 Long Question Preparation - Set 2

How we can find the density of an object

State and explain Young's modulus.

Define elasticity. explain deforming force, stress, strain and tensile strain.

Explain how submarine moves up the water surface down into water

Q no 5 (B) How much would be the volume of ice formed by freezing 1 liter of water.

Define atmospheric pressure . explain it

Q no: 5 (A) Derive the formula of Young Modulus.?

Define pressure. explain it with examples

Explain breaking system in vehicles

State and explain Archimedes principle. Also prove it

9th class Physics Chapter 7 Long Q's (English Medium)

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