Work, Energy and Power
This lesson covers the definitions of work, energy, and power. It includes calculations for work done, gravitational potential energy, and power in watts. The lesson also distinguishes between kinetic and potential energy and explains energy transformation and the law of conservation of energy.
- 10:30 “Take, for example, hot water and cold water. The temperature difference between them, most of the way, you pour hot water or cold water in hot water, the hot water will supply heat to the cold water. So that at the end o...”
- 22:29 “An example, an object of mass 5 kilogram moves with a speed of 10 meter per seconds, calculates the kinetic energy of the object. Now, if our kinetic energy is 1/2 M v square, and from the question, our M equals 5 kilogr...”
- 17:50 “And two, the speed before hitting the ground or striking the ground. In solving this, for our potential energy, we have an example. A mango of mass 1.5 kg is dropped from a height 40 meter above the ground. If G equals 1...”
Work, Energy and Power
This lesson covers the definitions of work, energy, and power. It explains potential and kinetic energy as forms of mechanical energy. The lesson also includes calculations related to work done and the concept of power as the rate of doing work.
- 10:42 “Remember, I said energy cannot be destroyed. Now, if you look at the diagram before you on the screen, you see a young man holding a catapult. The energy stored in this particular catapult is referred to as potential ene...”
- 13:19 “So, our potential energy will be 20 kg, which is the mass of the body multiplied by the height, which is about 8 m and the acceleration due to gravity, which is 10 Newton/kg. We obtained 1,600 joules, which is the unit o...”
- 04:52 “And the formula is seen as force times distance. And it is named by a particular man known as James Prescott Joe. James Prescott Joe was a scientist who carried out a lot of research in field of energy and work done. His...”
Sources of Energy
The lesson covers different sources of energy, including renewable and non-renewable types. It explains how energy is used in society and discusses the environmental impacts of various energy sources. Specific examples include petroleum, natural gas, solar energy, and wind energy.
- 10:58 “These are the energies that can never be replaced. After they are being used, they can never be replaced again. Now, we have, for example, as nuclear energy, when this one is being replaced in the environment, it can nev...”
- 10:10 “Or these are energy that can be replaced. Now, we have energy that can be replaced. After they are being used, we are to replace it back so that it can be able to be used in another form. When these energy are being used...”
- 00:02 “Good day, class. My name is Eme Nnamdi John. I'll be taking you on physics, through the topic, energy and society. Now, our first objective today, at the end of the study, Lena should be able to know one, the source of e...”
Gravitational Force and Fields
The lesson covers the concept of gravitational fields and the laws of gravitational force as proposed by Isaac Newton. It explains the relationship between masses and the distance between them in determining gravitational force.
- 16:52 “the distance, which is R. This can take care of this. By so doing, we have our work done, which give us work done is equal to big G M1, M2 over R, which we produced here. Now, we can say from kinetic energy, from kinetic...”
- 17:43 “we have what's the work done, work done is equal to kinetic energy. Now what is our work done, we have the G M1, M2 over R is equal to kinetic energy, which is one over two MV square, now, I can take care of this M, I ca...”
- 20:14 “now, what am I going to do to make this any of this a subject of the formula, let's make M as this, impute M into this place, I will have it to be, to be this, we already have mass of H to be this, we have that V is equa...”
Projectile Motion
This lesson covers the definition of projectile and projectile motion. It explains the concepts of time of flight, maximum height, and range, along with the relevant equations and examples from sports and warfare.
- 03:57 “Just like we said in the last session that when an object is projected vertically upward, it will get to a particular height that it will be able to move upward again. It will stop momentarily before coming down. And tha...”
- 07:13 “The maximum height is represented with capital letter H. The highest vertical distance attained by projectile as measured from the horizontal plane of projection is the highest vertical distance attained. So our H to fin...”
- 09:42 “Now, we want to get the range. Now, we are going to make use of the equation R which is H equal to U T plus R GT squared. Now on the horizontal plane according to the definition of range, there is no gravity on the horiz...”