Equations

Question 1

P = v x I

Answer 1

Power = voltage x current.

Power = watts (w)
Voltage=volts (v)
Current=amps (A)

Question 2

V = I x R

Answer 2

Voltage = current x resistance

Voltage=volts
Current =amps
Resistance=ohms

Question 3

Total cost

Answer 3

Number of units x cost per unit

Question 4

Efficiency (%)

Answer 4

(Useful energy out ( divided ) total energy in ) x100.

Energy(GPE,KE,WORK)=JOULES

Question 5

Gpr = mgh

Answer 5

Gravitational potentail energy = mass x gravity x height

Gravity=newtons
Energy(GPE,KE,WORK)=JOULES
mass=kilograms
Distance(including height)=meters

Question 6

Ke = 1/2mv2.

Answer 6

Kinetic energy = 0.5 x mass x velocity2

Energy=joules
Mass=kilograms
Speed(final velocity)= meters per second

Question 7

W = f x d

Answer 7

Work done = force x distance

Work done =joules
Force=newtons
Distance=meters

Question 8

W=E

Answer 8

Work done = energy trasferred

Both = joules

Question 9

P= e % t.

Answer 9

Power= energy % time

Power =watts
Energy = joules
Time = seconds

Question 10

S = d % t

Answer 10

Speed = distance % time

Speed = meters per second
Distance =meters
Time = seconds

Question 11

A = (v-u) % t

Answer 11

Acceleration = change in velocity % time

Acceleration =meters per second squared
Speed(final velocity)= meters per second
Time=seconds

Question 12

W= m x g

Answer 12

Weight = mass x gravity

Question 13

V = f x λ

Answer 13

Wave speed = frequency x wavelength

Wave speed =m/s
Wave freqency = hertz
Wavelenght = meters

Question 14

F = k x e

Answer 14

Force applied = spring constant x extension

Force=newtons
Spring contest = newtons per meter
Extencion= meters