Topic 8 (mechanics)

Question 1

gravity

Answer 1

9.8m/s squared

Question 2

mathematical modelling

Answer 2

constructing models to stimulate real life situations

Question 3

constructing mathematical model

Answer 3

real world problem 
set up mathematical model (assumptions/variables ?)
solve and interpret 
answer realistic? 
yes = report solution 
no = reconsider assumptions

Question 4

SI units

Answer 4

(international system of units ) are base units mosts commonly used in mechanics

mass = kg 
length/displacement = m 
time = s

Question 5

modelling assumptions

Answer 5

mind map in folder

Question 6

scalar and vectors

Answer 6

scalar: magnitude (size) no direction (always positive)
vector : magnitude and direction (positive or negative)

distance = scalar 
displacement = vector 

speed = scalar 
velocity = vector 

position = scalar 
vector = vector

Question 7

mass vs weight

Answer 7

mass is measured in kg

weight is a force measured in N

Question 8

forces

Answer 8

magnitude and direction (vectors )
magnitude of a force - Newtons
direction = angle or bearing
usually shown as force diagrams

Question 9

normal reaction force

Answer 9

particle in contact with surface then force acts perpendicular or normal to surface counteracts weight of particle

equilibrium= balanced forces (stationary)(no acceleration)

Question 10

friction force

Answer 10

horizontal force is applied to a book a frictional force will act in opposite direction to motion, resistance to motion caused by rough surface = friction
magnitude of fictional force depends on roughness of surface

Question 11

tension or thrust

Answer 11

object being pulled along by string force action on object called tension in the string

object being pushed along using a light rod force acting on object is called thrust in the rod

Question 12

resistance

Answer 12

object moving through the air or fluid will experience resistance due to friction between object and air or fluid force opposed motion of object

Question 13

vectors in mechanics

Answer 13

position= distance/direction from origin 
displacement= distance in particular direction m
velocity = rate of change of displacement m/s
acceleration= rate of change of velocity m/s squared 
force = described by magnitude direction and point of application (n)

Question 14

scalars in mechanics

Answer 14

time= measure of ongoing events taking place s 
mass = measure of quantity of matter contained in an object kg 
distance = measure of length (magnitude of displacement vector) 
speed = measure of how quickly a particle moves (magnitude or velocity vector m/s)