Equations to learn:
Equations for constant acceleration
s = displacement (m)
u = initial velocity (m/s)
v = final velocity (m/s)
a = acceleration (m/s^2)
t = time (s)
v = u + at (no s)
s = 1/2 (u + v) t (no a)
s = ut + 1/2at^2 (no v)
s = vt - 1/2at^2 (no u)
v^2 = u^2 + 2as (no t)
When solving kinematic quesitons:
Example
A cat is walking at 9 m/s and comes to a stop after 5 metres. Deceleration was constant. Find out how long it took the cat to come to rest.
S = 5m
U = 9 m/s
V = 0 m/s
A = n/a
T = ?
s = 1/2 (u + v) t
5 = 1/2 (9 + 0) t
5 =4.5t
t = 10/9 s
s = displacement (m)
u = initial velocity (m/s)
v = final velocity (m/s)
a = acceleration (m/s^2)
t = time (s)
v = u + at (no s)
s = 1/2 (u + v) t (no a)
s = ut + 1/2at^2 (no v)
s = vt - 1/2at^2 (no u)
v^2 = u^2 + 2as (no t)
When solving kinematic quesitons:
- Write down S U V A T in a vertical line
- Fill in values from the question
- Generally you are given 3 values and asked to work out a 4th, so find what the question doesn't need initially( could be a two parter) and find the equation without it
- Fill in the numbers and solve for the unit you want
Example
A cat is walking at 9 m/s and comes to a stop after 5 metres. Deceleration was constant. Find out how long it took the cat to come to rest.
S = 5m
U = 9 m/s
V = 0 m/s
A = n/a
T = ?
s = 1/2 (u + v) t
5 = 1/2 (9 + 0) t
5 =4.5t
t = 10/9 s
The Quadratic Equation
The quadratic equation is used for solving quadratic equations in the form :
a^2 + a + 0
Each part corresponds to a letter which is used in inputting the numbers into the formula.
So for example:
2x^2 + 4x + 3 = 0
a b c
Then after inputting the numbers you will receive two numbers (one using minus, one using plus) and these will be your answers
The quadratic equation is used for solving quadratic equations in the form :
a^2 + a + 0
Each part corresponds to a letter which is used in inputting the numbers into the formula.
So for example:
2x^2 + 4x + 3 = 0
a b c
Then after inputting the numbers you will receive two numbers (one using minus, one using plus) and these will be your answers