kinematics

define displacement

the straight line distance joining an initial and final point

units for displacement

meters (m)

define velocity

the rate of change of displacement

units for velocity

m/s

define acceleration

the rate of change of velocity

units for acceleration

m/s^2

what is represented by the gradient of a displacement-time graph?

velocity

what is represented by the gradient of a velocity-time graph?

acceleration

what is the shape of a displacement-time graph of an object with uniform velocity?

straight line, constant gradient.

what is the shape of the velocity-time graph of an object with increasing acceleration?

a line sloping upwards with an increasing gradient

what is represented by the gradient of a displacement-time graph changing from positive to negative?

object has changed direction

what is represented by velocity-time graph crossing the x-axis?

object has changed direction

what is represented by the area under a velocity time graph?

object displacement

what is meant by an object in free fall?

object is only under the influence of gravity (9.81ms^-2)

describe how the velocity of an object changes when falling in uniform gravitational field without air resistance:

- velocity decreases with a uniform acceleration of 9.81ms^-2

- velocity increases 9.81ms^-1 per second

describe the motion of projectile

projectile of an object has 2 dimensions under the influence of gravity, has the path of a parabola

parabola

a symmetrical open plane curve that the path of a projectile under the influence of gravity follows.

S =

(u+v/2)t

v^2

u^2 + 2as

a =

(v-u)/t

s =

ut + 1/2at^2

s

displacement (m)

u

initial velocity (ms^-1)

v

final velocity (ms^-1)

a

acceleration (ms^-2)

t

time (s)

SUVAT can only be used...

in equations of motion where object moves in a constant, uniform acceleration in a straight line