Most Recent Posts

Gas Laws and the Kinetic Theory of Gases

When an inflated balloon is left out in the sun, it increases in volume without extra air being pumped in. If the balloon is taken out of the sun and placed in a cold room, the volume reduces without any air escaping. Out in the sun, the temperature of air in the balloon rises and the gas expands leading to an increase in volume. In the cold room, the temperature of the air in the balloon reduces and consequently the air contracts hence volume reduces. This implies that when temperature of air (gas) increases, the volume of the gas increases and vice versa. For this to happen, the pressure and mass of the gas must be kept constant. Hence;...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 1 2018 Solved

Past Paper...read more.

Dr. Margaret W. Chege


Circular Motion

Circular motion refers to motion along a curved path e.g., a roundabout. Suppose an object moving along a circular path of radius r covers a distance represented by the arclength AB (a section of the circumference of a circular path of a circle is referred to as arclength), sweeping an angle  about the center O....read more.

Dr. Margaret W. Chege


Upthrust, Viscosity and Terminal Velocity

Objects float if they are less dense than, or of equal density with, the fluids (liquids and gases) they occupy. For example, while steel is denser than water, a steel ship can be made to float by introducing air-filled chambers which reduce the density of the ship relative to that of water. Floating bodies usually have part (or all) of their bodies in the liquid and as a result experience an upward force called upthrust (or buoyant force). Consider for instance an object of mass m, cross-sectional area and height fully submerged in a liquid of density ρ....read more.

Dr. Margaret W. Chege


Pressure, Continuity and Bernoulli's principles

Pressure refers to the force a body exerts perpendicularly per unit surface area i.e....read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 1 2019 Solved

Past Paper...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 1 2020 Solved

Past Paper...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 1 2021 Notes

Past Paper...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 2 2019 with notes

Past Paper...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 2 2020 with notes

Past Paper...read more.

Dr. Margaret W. Chege


KCSE PHYSICS PAPER 2 2021 with notes

Past Paper...read more.

Dr. Margaret W. Chege


Linear Motion, Newton's Laws, Friction

When an object moves along a line, it is said to undergo linear motion. If it moves along a circular path or a bend, it is said to undergo circular or rotational motion. If the object moves to-and-fro about a mean position, it is said to undergo vibratory or oscillatory motion. ...read more.

Dr. Margaret W. Chege