Equations

Question 1

Equation linking current, resistance and voltage

Answer 1

Resistance = p.d./current

Question 2

Equation that links speed time and distance

Answer 2

Distance = Speed x Time

Question 3

Equation for acceleration

Answer 3

Acceleration = Change in Velocity/Change in Time

Question 4

Equation for gravitational field strength

Answer 4

Gravitational field strength = force/mass

Question 5

Equation for Spring Constant

Answer 5

Spring constant = force / extension

Question 6

Equation for gravity

Answer 6

Gravity = weight / mass

Question 7

Equation linking force, mass and acceleration

Answer 7

Force = Mass x Acceleration

Question 8

Equation for a moment

Answer 8

Moment = Force x Perpendicular distance

Question 9

Equation for momentum

Answer 9

Momentum = Mass x Velocity

Question 10

Equations for impulse

Answer 10

Impulse = Force x Change in time
Impulse = Change in mass x velocity

Question 11

Force

Answer 11

mass (kg) × acceleration (ms-2)

Question 12

Density (kgm-3)

Answer 12

mass (kg)
volume (m^3)

Question 13

Force (N)

Spring Constant

Answer 13

constant (Nm-1) × extension (m)

Question 14

Pressure (Pa)

Answer 14

force (N) /area (m^2)

Question 15

Fluid Pressure (Pa)

Answer 15

density (kgm-3) × gravitational field strength (ms-2 or Nkg-1) × height (m)

Question 16

Work (J)

Answer 16

force (N) × distance moved (m)

Question 17

Power (W)

Answer 17

work (J) / time (s)

Question 18

Kinetic Energy (J)

Answer 18

½ × mass (kg) × velocity2 (ms-1)

Question 19

Gravitational potential energy (J)

Answer 19

mass (kg) × gravitational field strength (ms-2 or Nkg-1) × height (m)

Question 20

Efficiency (%)

Answer 20

useful power output (W or J) × 100
total power input (W or J)

Question 21

Force (N)

Answer 21

change in momentum (kgms-1) / time (s)

Question 22

Orbital Period (s)

Answer 22

2 × π × radius (m) / velocity (ms-1)

Question 23

Boyle’s law

Answer 23

pressure1 (Pa) × volume1 (m3) = pressure2 (Pa)× volume2 (m3)

Question 24

Energy (J)

heat capacity

Answer 24

mass (kg) × specific heat capacity (Jkg-1°C-1) × temperature change (°C)

Question 25

Thermal capacity (J°C-1)

Answer 25

mass (kg) × specific heat capacity (Jkg-1°C-1)

Question 26

Energy transferred (J)

heat

Answer 26

mass (kg) × specific latent heat (Jkg-1)

Question 27

Current (A)

Answer 27

charge (C) / time (s)

Question 28

Voltage (V)

Answer 28

energy transferred (J) / charge (C)

Question 29

Voltage (V)

Answer 29

current (A) × resistance (Ω)
V = IR

Question 30

Power (W)

Answer 30

current (A) × voltage (V)
P = IV

Question 31

Power (W)

Answer 31

current^2 (A) × resistance (Ω)
P = I^2R

Question 32

Energy transferred (J)

Answer 32

current (A) × voltage (V) × time (s)
ΔE = IVt

Question 33

Energy transferred (J)

show

Answer 33

power (W) × time (s)
ΔE = Pt
ITV

Question 34

Wave speed (ms-1)

Answer 34

frequency (Hz) × wavelength (m)

Question 35

Refractive index

Answer 35

=speed of light in vacuum / speed of light in material

Question 36

Energy (J)

Nuclear

Answer 36

mass defect (kg) × speed of light ^2
(ms-1)

Question 37

Hubble constant

Answer 37

2.2 × 10–18 per second

Question 38

Age of the universe

Answer 38

1 / Hubbles constant