Teach Start up for session 2018-19

Teaching Physics is much easier to teach for the teacher and same easier for the learner to learn -- IF -- Physics is taught NOT by lectures and learnt by performing .

Magnetic Lines of Forces

Curved lines used to represent a magnetic field, drawn such that the number of lines relates to the magnetic field's strength at a given point and the tangent of any curve at a particular point is along the direction of magnetic force at that point.

The direction of the field is always north to south while in a solenoid we observe the same phenomena but in more detail.

pressure in liquids, solids and gases

Pressure:

Pressure is the amount of force acting per unit area. The symbol for it is p or P

• Pressure inside liquids are due to the random movement of the liquid molecules and the weight of the liquid. The pressure inside solids occurs only due to the weight of the solid.

•  The liquid pressure acts on the sides of the liquid as well as the bottom. The pressure due to solids only appears at the bottom of the solid.

I will suggest the following videos by TED.Ed on www.youtube.com. Links are given below

https://www.youtube.com/watch?v=EkDhlzA-lwI

https://www.youtube.com/watch?v=VDf00z8sMFw

I hope you would find it helpful.

Welcome Back after winter break

Dear Students and all readers you are all welcomed back for the support in content for the 2nd term of session 20116-17.

Regards

Forces: online assignment for 9CB

Dear learners
   watch the following videos and submit your online test that has been emailed you on your gmail accounts

https://www.youtube.com/watch?v=LYXGlXMi6_c

https://www.youtube.com/watch?v=kKKM8Y-u7ds

Regards

Kashif Jamal

Heat Capacity and Specific Heat Capacity

 Heat Capacity:

Heat Capacity, C, of a body is defined as the amount of heat (Q) required to raise its temperature (θ) by one degree, without going through a change of state. 

• Amount of heat needed to raise the temperature of an object depends on the mass of the object.
• Heat capacity also depends on the material of the object. Some materials are harder to heat up than others. In order to record 1°C increase in temperature, liquids would require more heat energy than solids.
• SI. unit of heat capacity is joule per kelvin (J K^-1) or joule per degree Celsius (J °C^-1).

C=QΔθ
 , where
C = heat capacity (JK^-1, J°C^-1)
Q = heat or thermal energy absorbed or released (J)
Δθ = change in temperature (K or °C)

 Specific Heat Capacity: 

Specific heat capacity, c, of a body is defined as the amount of heat (Q) required to raise the temperature (θ) of a unit mass of it by one degree, without going through a change in state.

• When the mass of an object is greater, the object will contain more atoms or molecules than a less massive object made up of the same material. Hence, when the temperature of the objects are raised, the more massive object will require a larger thermal energy than the less massive object. (Analogy: The more massive object has more “mouths” to feed) It is thus more common to consider the heat capacity per unit mass or specific heat capacity of the body.

SI unit of specific heat capacity is joule per kilogram per kelvin (J kg^-1 K^-1) or joule per kilogram per degree Celsius (J kg^-1 °C^-1)
Q=mcΔθ

Thermal Energy and Temperature

Thermal Energy:
 Thermal energy is a form of internal energy. Thermal energy is possessed by all material matter and manifest as the random motion of atoms and small particles. The amount of thermal energy depends on the temperature of the matter.

Temperature:
Temperature is a measure of the degree of hotness or coldness of a body.

Transfer of Thermal Energy:
Thermal energy may be transferred from one region to another as a result of a difference in temperature via thermal:

1. conduction 
2. convection 
3. radiation 

Thermal energy flows from a higher temperature object to a lower temperature object. However, this heat exchange will cease when both objects reach thermal equilibrium (same temperature).
Important:
Temperature is not the equivalent of the total energy contained in a body. The total energy contained in a body is comprised of other forms of energy as well.