Formulas (Unit 1) Flashcards
1
Q
Moment of a Force
A
Moment = Force = Perpendicular distance from pivot
M = F × D
2
Q
Equations of motion
A
v = u + at
s = ½(u + v)t
s = ut + ½at²
v² = u² + 2as
3
Q
Average velocity
A
Average Velocity = Total displacement ÷ Total time taken
4
Q
Impulse
A
F × t
Ft = mv - mu
5
Q
Momentum
A
p = mv
6
Q
Acceleration
A
a = (v - u) ÷ t
7
Q
Force
A
F = ma
8
Q
Work done
A
Wd = f × d
Wd = ½mv² - ½mu²
Wd = QV
9
Q
Potential Energy
A
p.e. = mgh
10
Q
Kinetic Energy
A
k.e. = ½mv²
11
Q
Efficiency
A
Efficiency = useful output energy ÷ total input energy
12
Q
Power
A
P = wd ÷ t
P = energy transfered ÷ time taken
P = Fv
P = IV
P = I²R
P = V² ÷ R
13
Q
Charge
A
Q = It
14
Q
e.m.f.
A
E = W ÷ Q
15
Q
Voltage
A
V = IR
16
Q
Resistance
(Resistivity)
A
R = ρl ÷ A
17
Q
e.m.f. of a cell
A
E = V + v
E = V + Ir
E = IR + Ir
E = I(R + r)
18
Q
Potential Divider
A
I = Vᵢₙ ÷ (R₁ + R₂)
Vₒᵤₜ = I × R₁
Vₒᵤₜ = (R₁Vᵢₙ) ÷ (R₁ + R₂)
