lecture 9 Flashcards
(31 cards)
in linear motion, the most basic kinematic variables are:
displacement, velocity and acceleration
in angular motion, the equivalent kinematic variables are:
angular displacement, angular velocity and angular acceleration
an angle is formed by the interaction between what?
2 lines, 2 places and one line and one plane
if 1 line or place is fixed what is the angular position?
absolute angular position
if other line or plane is capable of moving what is the angular position
relative
what is angular displacement measured in?
degrees or radians
angular displacement vs angular distance?
displacement = vector
distance - scalar
what does angular displacement have
both magnitude and direction, positive and negative values
how do we decide on the negative and positive direction?
clockwise displacement is negative
anti-clockwise displacement is is positive
what is the equation for angular velocity ?
change in angular displacement divided by change in time
what is the equation for angular speed?
change in angular distance divided by change in time
what is concentric force?
line of action passes through the CoG
What is eccentric force?
line of action that does not pass through the CoG
what does concentric force cause?
change in linear motion
what does eccentric force cause?
change in linear and angular motion
what would happen if you pull someone below their centre of mass?
you would fall
what is torque (moment of force)?
the turning effect produced by a force.
torque is a vector, thus having positive and negative values.
what is the equation for torque?
T = F . d torque = force (N) multiplied by the distance
why is torque have positive and negative values?
torque is a vector and had positive(anti clockwise) and negative(clockwise) rotation.
what is magnitude?
the size or extent of something
what can increase torque?
increasing the magnitude(size) of the force and increasing perpendicular distance from the axis of rotation
why are door handles located on the opposite side from the hinges?
the further away the handle is from the hinges the easier it is to open the door
how does force direction affect torque?
the line of action of the force is crucial, as it affects the perpendicular distance from the axis of rotation
toque in human body?
body limbs rotate around our joints.
