Home » Blog » O level Physics Revision » Physics laws and formulae (O level) # Physics laws and formulae (O level)

## Physics laws and formulae (O level)

This list is a list of physics laws and formulae used in O level physics.

### Kinematics

• • • • #### Equations of motion with constant acceleration

• • • • ### Density

• ### Hooke’s law

• Hooke’s law – that the extension was of a material is proportional to the stretching force provided the material is not permanently stretched.

• ### Forces

• Parallelogram law – If two forces acting at a point are represented in size and direction by the sides of a parallelogram, their resultant is represented in size and direction by the diagonal of the parallelogram drawn at that point.

• Newton’s first law of motion – A body stays in its state of rest or uniform velocity unless acted upon by an external force.

• Newton’s second law of motion – The acceleration of a body is directly proportional to the resultant force acting on it.

• Newton’s third law of motion – To every action there is an equal and opposite reaction.

• • ### Circular motion

• ### Moments

• Law of moments – When a body is in equilibrium the sum of the clockwise moments about any point is equal to the sum of the anticlockwise moments about the same point.

• moment of a force = force × perpendicular distance of the line of action of the force from the pivot

### Momentum

• ### Work, energy and power

• Law of conservation of energy – energy can neither be created nor destroyed but can be converted from one form to another.

• • • • • • • ### Pressure

• • ### Gas Laws

• Boyle’s law – The pressure of a fixed mass of gas is inversely proportional to its volume if its temperature is kept constant.

• Charles’s law – The volume of a fixed mass of gas is directly proportional to its absolute temperature if the pressure is kept constant.

• Pressure law – The pressure of a fixed mass of gas is directly proportional to its absolute temperature if the volume is kept constant.

• ### Thermal Physics

• • ### Waves and optics

• Law of reflection – The angle of incidence is equal to the angle of reflection.

• • • • ### Magnetism

• Law of magnetic attraction – Like poles repel, unlike poles attract.

### Electricity

• Law of electrostatic attraction – Like charges repel, unlike charges attract.

• Ohm’s law – The current in an ohmic conductor is directly proportional to the p.d. across its ends if the temperature is kept constant.

• • • • • • • • #### Resistors in series

• #### Resistors in parallel

• ### Electromagnetism

• Faraday’s law – The size of the induced p.d. is directly proportional to the rate at which the conductor cuts magnetic field lines.

• Lenz law – The direction of the induced current is such as to oppose the change causing it.

1. 