Physics

MEASUREMENT IN PHYSICS (CONT) Measurement of area and volume Concept & measurement of time and ways of measuring time. MEASUREMENT OF VOLUME Volume of liquid objects is measured using instruments such as cylinder, burette, pipette, eureka can, etc. For regular solid objects, their volume could be determined using their mathematical formula. S/N Solid Object Formula […]

FUNDAMENTAL QUANTITIES AND UNITS Fundamental quantities: mass, length, time and electric charge Simple measurement of current and temperature. CONCEPT OF FUNDAMENTAL QUANTITIES Fundamental quantities are physical quantities whose dimensions and units are not usually derived from other physical quantities. Basically, there are three fundamental quantities in mechanics. They include: Mass Length and i) Mass: This

Measurement of length Measurement of mass & weight MEASUREMENT OF LENGTH/DISTANCE Length is measured using the following instruments. (a). Metre Rule: A metre rule is a measuring device calibrated in centimetres (cm) with a range of 0 – 100cm. In using the metre rule, the eye must be fixed vertically on the calibration to avoid

Definition & Importance of Physics. Aspects/Career in Physics. Branches of physics. DEFINITION OF PHYSICS The word ‘’PHYSICS’’ originates from the Greek word, ‘’PHYSIS’’, which means nature and natural characteristics. Physics as a body of scientific knowledge, deals with the study of events in the universe, both remote and immediate universe. In actual sense, physics deals

X-rays were discovered by a German scientist named Roentgen in 1985. They can pass through most substances including soft tissues of the body but not through bones and most metals. They were named X-rays meaning ‘unknown rays’. X-ray production They are produced by modified discharge tubes called X-ray tubes. The cathode is in the form

What is cathode rays?. These are streams of electrons emitted at the cathode of an evacuated tube containing an anode and a cathode. Production of cathode rays They are produced by a set up called a discharge tube where a high voltage source usually referred to as extra high tension (EHT) supply connected across a

Sources of mains electricity Mains electricity comes from a power station and its current is the alternating current which can either be stepped up or down by a transformer.  A.c is produced when a conductor is rotated in a magnetic field or when a magnetic field is rotated near a conductor. This method is known

What is a Len?.  A lens is conventionally defined as a piece of glass which is used to focus or change the direction of a beam of light passing through it. They are mainly made of glass or plastic. Lens are used in making spectacles, cameras, cinema projectors, microscopes and telescopes. Types of thin lenses. A

Properties of waves Waves exhibit various properties which can be conveniently demonstrated using the ripple tank. It consists of a transparent tray filled with water and a white screen as the bottom. On top we have a source of light. A small electric motor (vibrator) is connected to cause the disturbance which produces waves. The

Energy This is the ability to do work. Forms of energy. Chemical energy: – this is found in foods, oils charcoal firewood etc. Mechanical energy:- there are two types; Potential energy – a body possesses potential energy due to its relative position or state Kinetic energy – energy possessed by a body due to its motion

Introduction Study of motion is divided into two; Kinematics Dynamics In kinematics forces causing motion are disregarded while dynamics deals with motion of objects and the forces causing them. Displacement Distance moved by a body in a specified direction is called displacement. It is denoted by letter‘s’ and has both magnitude and direction. Distance is

Sound is an important example of a longitudinal wave which is composed of both compressions and rarefactions. The frequency range in which compressional disturbances occur is called the sonic spectrum and is very large. Sound is a range of compressional wave frequencies sensitive to human ear and is known as audio range which ranges from

What is a wave?. A wave is simply a disturbance that moves through a medium . Other waves do not require a medium to travel i.e. they can travel in a vacuum, are known as electromagnetic waves e.g. radio, X-rays, gamma rays UV rays etc. Other waves require a material medium to be transferred and

Hooke’s law states that “the extension of a spring is proportional to the applied force, provided that the force is not large enough to deform the spring permanently”. Mathematically expressed as Force α extension. Spring constant Since Force α extension then Force / Extension = constant (k). The constant of proportionality (k) is called the

Concave and convex mirrors They are also known as spherical mirrors and are formed when a spherical glass is silvered . If the inside is silvered a convex or diverging is formed while a concave or converging mirror is formed when the outside is silvered. Parts of a spherical mirror. Centre of curvature (C)– this

Centre of gravity Centre of gravity or C.G is the point of balance of a body in which the total weight of the body seems to act through. For regular shaped bodies the C.G is at the geometric centre of the body. For irregular bodies their weight still acts at the centre of the gravity

Turning Effects The turning effect of a body is called the moment of that force. The turning effect produced depends on both the size of the force and the distance from the pivot. The moment of a force about a point is the product of the force applied and the perpendicular distance from the pivot

Introduction Magnets are substances that are able to attract and hold items. Lodestone is the only known natural magnet which was discovered by the Chinese 2,000 years ago. Other magnets produced artificially by man are called artificia l magnets. Magnets and non-magnetic materials Magnetic materials are those that are strongly attracted by magnets while non-magnetic