Equations

Question 1

Work equation

Answer 1

Work done (joules, J) = force (Newtons, N) x distance (meters, M)
W = F x d 
Work done = energy transferred

Question 2

Delta equation

Answer 2

Delta Ep v mg delta h
Waight = mass x gravitational field strength
Change in objects gravitational potential energy store = weight x change in hight

Question 3

Kinetic energy

Answer 3

Kinetic Energy (Joules, J) =1/2 x mass( Kilogram, Kg) x speed squared ( meters per second, m/s)

Question 4

Efficency

Answer 4

Efficency = useful output energy (J)/total input energy (J) x100

Question 5

Power watts

Answer 5

Power (watts, W) = energy transferred (J) / Time taken (s)

P=E/t

Question 6

Power =)

Answer 6

Power (w) = Current (amperes, A) x potential diffrence (Volts, V)

Question 7

Power *

Answer 7

P = I squared x R

Power (w) = current squared (A) x resistance (ohms, Ω)

Question 8

Charge flow

Answer 8

Charge flow (C)  = current (A) x time (s)
Q=Ixt

Question 9

Potential diffrence

Answer 9

V=E/Q
Potential diffrence (v) = Energy transferred (j) / charge (c)

Question 10

Resistance

Answer 10

R=v/I
Resistance (Ω)= potential difference (v) /current (A)
Or
Current (A) = potential diffrence / resistance

Question 11

Density

Answer 11

Denisty (ρ, rho) = mass (kg/m³) / Volume (m³)

Question 12

Moment

T

Answer 12

Moment (NM) = force(N) x distance (M)

Question 13

Moments in equilibrium

T

Answer 13

F¹ x d¹ = F² x d²
W is sometimes used instead of F 
F(N)
d(m)
(Not squaring the numbers)

Question 14

SUVAT

Answer 14

V=s/t 
a= v-u/t 
v²-u²=2as
V²=u²+2as
a=v²-U²/2s
A, avveleration (m/s²)
V, final velocity (m/s)
S, equations we consider this distance

Question 15

Resaltant force

Answer 15

Resaltant force = mass x acceleration

F= mxa

Question 16

Weight

Answer 16

Weight = mass x gravitational field strenth Newtons, kg Newton per kg, N/Kg
N g=9.81

Question 17

Springs force

Answer 17

Force applied to a spring = Spring Contant x extention

F = Kx e

Question 18

Momentum

Answer 18

Momemtum = mass x verlocity
Kg m/s. Kg. m/s
P=mxv

Other fact
In a closed system the total momentum befor the event is equal to the momentum after the event.

Question 19

Force (impact)

T

Answer 19

Force (N) = mass (kg) x change in velocity (m/s) / time taken (s)

F=m x Δv/ t

Other fact
The longer the impact time, the more the impact force is reduced!

Question 20

Pressure (solid)

T

Answer 20

Pressure (Pa) = force (N) / area (m²)

Pressure in solids

Question 21

Pressure (liquid)

T

Answer 21

Pressure (pa) = hight (m) x density (kg/m³) Gravitational field strength (N/kg)

Question 22

Wavespeed

Answer 22

V=f x λ
Wave speed (m/s)= frequancy (hz) x wavelength (m)

Question 23

Iam equation

Answer 23

Magnification = image hight / object height