Topics in PhysicsDerived Units: Similarities and Differences with Fundamental Units Gravity: Interesting facts on Gravity Relative Density of Substances and Specific Gravity Types of Heat Transfer: Conduction Types of Heat Transfer: Convection Types of Heat Transfer: Radiation Physics Scheme of Work, SS1, First Term Physics Scheme of Work, SS1, Second Term Physics Scheme of Work, SS1, Third Term Velocity and Acceleration Newton's Laws of Motion Importance of Gravity What is Density? Density of various Substances Concepts of Force and Motion Motion and Speed Concept of Heat Transfer Concepts of Heat and Temperature Gravity: What is Gravity? Zeroth Law of Thermodynamics - Thermal Equilibrium Fundamental Quantities and Units in Physics
Academic Questions in Physics
The Law of Inertia is also referred to as _____.
The process whereby the velocity of an object increases and decreases over a period of time is best associated with the term _____.
The rate of motion is best referred to as _____.
Consider this expression below:
A body X exerts a force FX on another body Y. In return, body Y exert a force FY back on body X. The forces FX and FY are equal in magnitude but opposite in direction.
Putting the above expression into equation:
FX = -FY
Where FX is the action force
FY is the reaction Force
The above expression relates to _____.
The tendency of a body to remain in a state of rest or in uniform motion is referred to as _____.
A change in the position of an object with reference to time is best described as _____.
The saying "what goes up on earth must come down" can be best attributed to _____.
We have _____ laws of Thermodynamics.
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Let's begin by considering the instance below:
When we pour in water of 100OC into an aluminium cup whose temperature is the same as that of its surrounding; let’s say 22OC; We will observe the followings:
Note: OC = degree centigrade; and it's a unit of temperature.
For now, think of temperature as the degree of hotness or coldness of a substance or an object with reference to some standard value.
From the above instance, it can be deduced that the heat present in the water molecules are first transferred to the aluminium cup and then to the surrounding.
Heat from water >>> Aluminium Cup >>> Surrounding
Note: Aluminium is a metal and metals are good conductors of heat.
Eventually, the system and the surroundings will reach the same temperature; and the heat transfer ceases. It is at this point, that the water, aluminium cup and the surroundings are said to have reached thermal equilibrium.
This above paragraph is the concept of the Zeroth law of thermodynamics.
Note: Although the surrounding receives heat from the water and aluminium cup, its temperature will remain approximately unchanged for the following reasons:
Heat is never lost because it is a form of energy; rather it will be transferred according to the First Law of Thermodynamics which states that:
Energy can neither be created nor destroyed but can be transferred from one form to another. Please read on the Law of Thermodynamics in Food Pyramid here.
Note: From our above instance, the transfer of energy (heat energy in this case) from the water to the aluminium cup and finally to the surrounding is referred to as Heat.
Heat can simply be explained as an energy that results from the transfer of energy from an object or substance or system with a higher temperature to another with a lower temperature.
Let consider another reverse instance with regards to heat:
Now, imagine that a cold bottle of water is brought out of the fridge into the kitchen. Assuming the temperature of water is 3OC while that of the kitchen environment is 22OC; the followings will occur:
Note: At no point did the coldness of the bottle or water escaped into the surrounding. Instead it is the temperature of the room that actually caused an increased temperature of the bottle and water (inside the bottle).
In fact, if the temperature of the room was higher than 22OC, heat transfer will be achieved at a much rapid rate. (That is; the rate at which the temperature of the water and bottle increases will be faster).
Since heat energy is being transferred from the kitchen surroundings to the bottle and then into the water; We can therefore conclude that heat will always be transferred from a higher region to a lower region until equilibrium is attained.
Heat is never static. It is always transferred and thus; an object will increase its temperature by gaining heat energy from its surroundings while another object simultaneously (at the same time) decreases its temperature by losing its heat energy to the surroundings. For this reason, we may also define temperature as:
The measure or ability of an object or substance to transfer heat energy to another object or substance.
The higher the temperature, the greater the ability of an object or substance to transfer heat. Conversely, the lower the temperature, the greater the tendency of an object to receive the transferred heat.
The point is:
For heat to be transferred, we must have systems or objects or substances with varying temperatures.
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Amazing facts in Physics
Image Credit: Ball and Roller Store
Glass Balls actually bounce higher than Rubber Balls
Every planet has its own unique gravitational force, for instance, Mars has a gravity of 3.711 m/s2 while earth’s gravitational force is 9.807m/s2. Please read on gravity here
When two metals are put together in space, they will stick together as if they are welded. This phenomenon is called cold welding
The fastest animal on land is Cheetah. It can reach a maximum speed of about 113km per hour.
Please read on motion, speed, velocity and acceeration here
NOTABLE POINTS IN Physics
The Classical Mechanics (Laws of Motion) is a fundamental part of Physics.
Below are the Newton's Laws of Motion:
An object at rest will continue in its state of rest; while an object in uniform motion will continue in a straight line, unless an external force acts on it.
Newton's First Law of Motion.
The rate of change of momemtum is proportional to the applied force and will take place in the direction of that force.
Newton's Second Law of Motion.
To every action, there is an equal and opposite reaction.
Newton's Third Law of Motion.
The study of Thermodynamics revolves around the relationship between heat, temperature, energy and mechanical work; and these can be summarised under the 4 laws of Thermodynamics (Numbered zero through three).
Below are the 4 laws of thermodynamics:
Zeroth law of thermodynamics – If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
1st law of thermodynamics – Energy can neither be created nor destroyed but can be changed from one form to another.
2nd law of thermodynamics – The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.
3rd law of thermodynamics – As temperature approaches absolute zero, the entropy of a system approaches a constant minimum.
Fuses are present in many electrical devices. They are basically 🔥 fire-breakers 🔥
If there is a power surge, the fuse will break, preventing damage to the electrical devices. It will also prevent the incidence of 🔥 fire🔥 on/from such device.
Physics is one of the core sciences.
Physics is defined the scientific study of matter and the movement of matter through the space and time of the universe.
Understanding the basic and fundamental concepts of physics will help you better comprehend this subject. Below are some of the concepts: