PHYSICS

Energy is the ability to do work. It exists in various forms and can be transferred or transformed from one form to another. Energy is essential in every aspect of life and drives all processes in nature and technology. Types of Energy 1. Mechanical energy 2. Thermal (Heat) energy 3. Chemical energy 4. Electrical energy 5. Nuclear (Atomic) energy 6. Sound energy 7. Light energy       Mechanical energy Mechanical energy is the energy that is possessed by an object due to its motion or due to its position. Types of mechanical energy The two types of mechanical energy are: 1. Kinetic Energy Kinetic energy is the energy of a moving object. The S.I. unit of kinetic energy is joules (J) Formula: K.E. = ½mv² where: m= mass (kg), v = velocity (m/s). Example: (i) What is the Kinetic energy of a 1500 kg car going at a speed of 14 m/s? Solution: K.E. = ½mv² m=1500kg, v=14m/s K.E=½ x 1500 x 14²       = 147,000J (ii) What is the velocity of a 1000 kg car if ...

A vector quantity is a physical quantity that has both magnitude and direction. Vector quantities are essential in understanding and solving problems in physics and engineering as they provide a complete description of physical quantities that involve direction. Examples of Vector Quantities 1. Displacement 2. Velocity 3. Acceleration 4. Force 5. Momentum Applications of Vector Quantities 1. Use for navigation by airplanes and ships to know their displacement and velocity 2. Use in physics to calculate forces in mechanics.  3. Use in Engineering for designing structures with force analysis Assignment Define the following: 1. Displacement 2. Velocity 3. Acceleration 4. Force 5. Momentum

Work is the product of force and the distance moved in the direction of the force. Work is done only when there is displacement in the direction of the applied force. It is a scalar quantity. Work = Force x Distance  Force = mass(m) x acceleration due to gravity (g) Force =mg Work = Force(mg) x Distance (h)           = mgh S.I unit of work is Newton-meter(Nm) or Joule (J) Example 1: A person pushes a box with a force of 50 N over a distance of 5 m in the same direction. How much work is done? Solution: Work = Force x Distance           = 50N x 5m           = 250Nm Example 2: An object is horizontally dragged across the surface by a 100 N force acting parallel to the surface. Find out the amount of work done by the force in moving the object through a distance of 8 m. Solution: Work = Force x Distance           = 100N x 8m           = 800J Example ...

A wave is a disturbance that transfers energy from one point to another without transferring matter. Types of Waves There are two major types of waves, namely: (a) Mechanic waves (b) Electromagnetic waves (a) Mechanical Waves A wave that requires a medium to travel through (e.g., water, air, solids). Examples of mechanical Waves: Sound waves, water waves, seismic waves. Types of mechanical Waves (i) Transverse waves (ii) Longitudinal waves Transverse Waves : In Transverse waves, the particles move perpendicular to the direction of wave propagation (e.g., water waves, light waves). Longitudinal Waves : The particles move parallel to the direction of wave propagation (e.g., sound waves). (b) Electromagnetic Waves They are waves that do not require a medium to travel. They can move through a vacuum. Examples: Light, radio waves, X-rays, microwaves etc Wave Parameters (i) Crest - The highest point on a wave (ii) Trough - The lowest point on a wave (iii) Wavelength (...