Mechanics 1 - Chapter 2 Kinematics - SUVAT Equations

1. Chapter 2 – Kinematics of a particle
moving in a straight line
s = displacement (m)
u = initial velocity (ms-1)
v = final velocity (ms-1)
a = acceleration (ms-2)
t = time (s)
When acceleration is constant
change in velocity v-u
acceleration=
change in time t
Rearranging gives
v=u+at i

2. displacement = average speed x time
u+v
s= t (ii)
2
Rearranging (i) to make t the subject and substituting
into (ii) gives
u+v v-u v 2 -u 2
s= =
2 a 2a
Rearranging gives
v 2 =u 2 +2as (iii)

3. We have
u+v
s= t (ii) and v=u+at i
2
Substituting (i) into (ii) gives
u+u+at 2u at 1
s= t= + t= u+ at t
2 2 t 2
1 2
s=ut+ at (iv)
2
Similarly u=v-at
v-at+v 2v at 1
s= t= t= v- at t
2 2 t 2
1 2
s=vt- at (v)
2