1. Prepared By: Shakil Raiman

2.  Density: Density of a substance is defined as its mass per unit volume.   Unit: kg/m 3, g/cm 3

3. For Regular Solid:  Measure the mass of the object.  Measure the dimensions. (Suppose for a cuboid length, width, and height)  Calculate volume by using dimensions. (Suppose for a cuboid Volume = length×width×height)  Calculate density by using formula density = mass/volume

4. For Irregular Solid:  Measure the mass of the object.  Take some suitable liquid within a measuring cylinder. The liquid should be enough so that the object sink completely. Measure the volume of the liquid. (V 1 )  Put the object into the liquid of the measuring cylinder. Measure the new volume of the liquid level. (V 2 )  Volume = V 2 – V 1  Calculate density. (density = m/ (V 2 – V 1 ))

5. For Irregular Solid:  Measure the mass of the object.  Take some suitable liquid within a displacement can. Wait for no liquid fall for the cal.  Put the object into the liquid and use measuring cylinder to measure the displaced liquid  Calculate density by using formula, density = mass/ volume.

6. For Liquid:  Take a measuring cylinder. Measure the mass of it. (m 1 )  Take the liquid within measuring cylinder. Read the volume of the liquid level. (V)  Measure the mass of the measuring cylinder with the liquid. (m 2 )  Mass of liquid = m 2 – m 1  Calculate density by using formula, density = mass/volume

7.  Mass: Mass of a body is the measure of the amount of matter that it contains.  Weight: Weight of a body is the attractive force exerted on it due to gravity.  Inertia: Any object tends to remain in its own state of rest or motion. Such tendency is called inertia.

8. Mass of an objectWeight of an object is always the samevaries from place to place is a measure of inertiais a measure of force is measured using a beam balance or an electronic balance. is measured using a spring balance or a compression balance is measured in kgis measured in N mass: 1 kgWeight on Earth: 10 N Weight on Moon: 1.6 N

9.  Pressure is force acting normally per unit area.  Pressure = Force / Area  Unit: Pascal (Pa), Nm -2, Ncm -2  If area is constant, Pressure increases if force increases and pressure decreases if force decreases.  If force is constant, pressure increases if area decreases pressure decreases if area increases

10.  We have air around us and therefore there is atmospheric pressure.  Atmospheric pressure exists because of molecular bombardment of energetic molecules.  The normal atmospheric pressure is about 1.013×10 5 Pa. It is called 1 atmosphere ( 1 atm. )

12.  The pressure due to a liquid column depends on the depth, height and the density of liquid.  Liquid Pressure = height × density × g  P=h  g

14.  Open end:  Pressure at X = P 0 +hpg  Close end:  Pressure at Y = hpg

15.  The pressure in a liquid depends on 1. the density of the liquid 2. the depth of the liquid  Note: the pressure in liquid does not depend on the area at any depth.  In the following picture, there is equal pressure at point A, B or C.

17.  Simple mercury barometer is used to measure atmospheric pressure.  Construction 1. a thick-walled glass tube ( about 1m long) is filled with mercury completely 2. the open end of the is covered with a finger and inverted 3. place the inverted tube in a mercury container  Observation: The height of the mercury column is found to be about  Atmospheric pressure=760 mmHg or 76 cmHg

18.  Manometer is used to measure gas pressure.  Construction: The manometer consists of a U-tube containing a column of liquid. The liquid can be mercury, water or oil.  Pressure of Gas = P 0 +hpg

19.  Pressure can be transmitted through a liquid in hydraulic presses and hydraulic brakes on vehicles.  A small force on smaller piston can cause greater force on greater piston.

20.  Wish you all very good luck and excellent result.