Always look for
Hidden quadratics and what we can make a quad
Interior angles
180 * (n-2)
Exterior angles
360/n
Do radioactivity questions
If in limiting equilibrium
F = uR
for scaling
SA = sf squared
Vol = sf cubed
when wave questions and distance travelled
USUALLY ASKS FOR PARTICLE WHICH IS ONLY UP AND DOWN
when dynamic equilibrium
Always set datum with ALL energy involved
If momentum q is starting from rest…
Can assume every moment taken, is also 0 momentum because no external force is applied
If spring in parallel
You add
If spring in series
Do as if it is resistors in para with 1/Rt
For mass flow rate questions…
If average force = mass flow rate (v-u)
Area of rhombus
pq/2
Area of parallelogram
bh
Transformers
Do questions..
How pistons work
If dia increases by k = force increases by k2
So distance moved = decreases by k2
Reaching thermal equilibrium…
Mc* delta t of metal = mc * delta t of water
Always check if radiation is being reflected
If distance travelled in eg. 4th second (from 4-5)
Do S (of 4-5) - S (of 3-4) = Sn = u + a(n-0.5)
If sum to infinity is a / 1-r
Then sum of squared is a2 / 1-r2
Nodal analysis questions…
Using remainder theorem..
Max values come from..
Stationary points ( see tmua)
Current:
- Can only take a closed loop
- two points on a wire which are connected have the same potential
