Linear motion & angular motion Flashcards
Scalar quantities
Size
- mass
- inertia
- distance
- speed
Vector quantities
size and direction
- weight
- acceleration
- deceleration
- displacement
- velocity
- momentum
Mass
made up of bone, muscle, fat, tissue and fluid and measured in kg
Weight
force on given mass due to gravity.
mass x gravity = weight
Distance
the length of the path a body follows when moving from one position to another
Displacement
the length of a straight line joining the start and finish points
Speed
rate of change of position
speed (m/s) = distance covered (m) / time taken (s)
Velocity
rate of change of position with reference to direction
velocity (m/s) = displacement (m) / time taken (s)
Acceleration
acceleration = (final velocity - initial velocity) / time taken
Momentum
product of mass and velocity of an object
momentum (kgm/s) = mass (kg) x velocity (m/s)
Impulse
time it takes a force to be applied to an object or body
Impulse= force x time
Angular motion
occurs when a force is applied outside the centre of mass
Torque
angular motion occurs as a result of torque- this is a turning force.
Newtons 1st law of linear Motion
rotating body will continue to turn about its axis of rotation with constant angular momentum unless and external torque is exerted upon it.
Newtons 2nd law of angular motion
rate of change of angular momentum of a body is proportional to the force causing it and the change that takes place in the direction in which the force acts
Newtons 3rd law of angular motion
when a force is applied by one body to another, the second body will exert an equal and opposite force on the other body.
Angular displacement
smallest change in angle between the start and finishing point of a rotation
Angular velocity
The rotational speed of an object and the axis about which the object is rotating
angular velocity (rad/s) = angular displacement (rad) / time taken (s)
Angular acceleration
the rate of change of angular velocity over time
angular acceleration (rad s2) = change in velocity (rad/s) / time taken (s)
Moment of inertia
the resistance of a body to angular motion (rotation)
moment of inertia (kg m2) = mass (m) x distribution of mass from the axis (m2)
Moment of inertia 2 factors:
- mass of the body
- distribution of mass from the axis of rotation
Angular momentum
the quantity of rotation a body possesses. involves an object or body in motion around an axis
angular momentum (kg m2 rad/s) = moment of inertia (kg m2) x angular velocity (rad/s)
