02. Mechanics

A measure of the separation between two points

Distance in a given direction

The rate of change of distance with respect to time

The rate of change of displacement with respect to time.

the rate of change of velocity with respect to time.

A quantity that has magnitude
only and has no direction

A quantity that has magnitude and direction

Anything that causes the velocity of an object to change

A measure of how difficult it is to accelerate a body.

A force of 1 Newton gives a mass of 1 kg an acceleration of 1 m s⁻²

The weight of an object is the force of the Earth’s gravity acting on it.

A body will remain at rest or travelling with constant velocity unless an unbalanced force acts on it.

When an unbalanced force acts on a body the rate of change of momentum is directly proportional to the force and takes place in the direction of the force.

When object A applies a force on object B,
then object B applies an equal but opposite force on object A

In any interaction between two or more bodies the total momentum before is equal to the total momentum after provided no external forces act on the system of bodies.

The mass per unit volume of a substance.

Force per unit area.

(When it is is partially or completely immersed in a fluid)
The upthrust on an object is equal to the weight of the fluid displaced.

states that the weight of a floating
body is equal to the weight of the fluid it displaces.

Pressure is inversely proportional to volume
for a fixed mass of gas at constant temperature.

states that the force between two bodies is directly proportional to the product of their masses and is inversely proportional to the square of the distance between them.

Force × Perpendicular Distance

• The vector sum of the forces in any direction is zero.
• The sum of the moments about any point is zero.

The Centre of Gravity of an object is the point through which all the weight appears to act.

A rigid body which is free to rotate about a fixed point called a fulcrum

Two parallel forces with the same magnitude acting in opposite
directions

When a force F moves a body through a displacement s in the direction of the force,

the work W done is equal to the force multiplied by the displacement.

1 joule is the work done when a force of 1 N displaces an object by 1 m

The ability to do work.

Energy cannot be created or destroyed.

the energy that a body has due to
its motion.

the energy a body has
due to its position in a force field.

A source of energy that does not get used up

A source of energy that will eventually run out

Power is the rate at which
work is done.

or

Power is the rate at which
energy is converted.

**know both**

1 Watt = 1 Joule per Second

the rate of change of angle with respect to time.

the force towards the centre of a circle
that keeps an object moving in a circle

the acceleration towards the centre
keeping a body in a circle

The time taken for a satellite
to complete one revolution
around the central body

(When an object is bent, stretched, or compressed)
The restoring force is proportional to the displacement.

SHM is defined as motion where

an object's acceleration is directly proportional to its displacement from a fixed point

and is always directed towards that point.

*• A mass vibrating up and down at the end of a spring moves with SHM.

• Each prong on a vibrating tuning fork moves with SHM.

• The projection of uniform circular motion on a diameter is SHM

• For a small angle of swing a pendulum moves with SHM.

•The tides coming in and out every 6 hours move with SHM

•A magnet suspended horizontally from a piece of thread moves with . SHM if it is displaced slightly from being aligned North-South

*
w = √(k ÷ m)

OR

w² = k ÷ m

A quantity with magnitude but no direction4

A quantity with magnitude and direction