Physics Equations You Must Learn Off By Heart

Question 1

How do you find weight?

Answer 1

Weight (N) = Mass (kg) x Gravitational field strength (N/kg)

( W = m x g )

Question 2

How do you find work done?

Answer 2

Work done (J) = Force (N) x Distance (m)

( W = F x s )

Question 3

How do you find force applied to a string?

Answer 3

Force applied to a string (N) = Spring constant (N/m) x extension (m)

( F = k x e )

Question 4

How do you find distance travelled?

Answer 4

Distance travelled (m) = Speed (m/s) x Time (s)

( S = v x t )

Question 5

How do you find acceleration?

Answer 5

Acceleration (m/s2) = Change in velocity (t) / Time taken (s)

( a = △v / t )

Question 6

How do you find resultant force?

Answer 6

Resultant force (N) = mass (kg) x acceleration (m/s2)

( F = m x a )

Question 7

How do you find momentum?

Answer 7

Momentum (kgm/s) = mass (kg) x velocity (m/s)

( p = m x v )

Question 8

How do you find kinetic energy?

Answer 8

Kinetic energy (J) = 0.5 x Mass (kg) x (Speed)2 (m/s)2

( E = m x (v) )

Question 9

How do you find gravitational potential energy?

Answer 9

Gravitational potential energy (J) = mass (kg) x gravitational field strength(g) (N/kg) x Height (m)

( Ep = m x g x h )

Question 10

How do you find power in terms of energy transferred?

Answer 10

Power (W) = Energy transferred (t) / time (s)

( P = E / t )

Question 11

How do you find power in terms of work done?

Answer 11

Power (P) = Work done (t) / Time (s)

( P = W/t )

Question 12

How do you find efficiency in terms of energy transfer?

Answer 12

Efficiency = Useful output energy transfer (J) / Total input energy transfer (J)

Question 13

How do you find efficiency in terms of power?

Answer 13

Efficiency = Useful power output (J) / Total power input (J)

Question 14

How do you find wave speed?

Answer 14

Wave speed (m/s) = Frequency (Hz) x Wavelength (m)

( v = f x λ )

Question 15

How do you find charge flow?

Answer 15

Charge flow (C) = Current (A) x Time (s)

( Q = I x t )

Question 16

How do you find potential difference?

Answer 16

Potential difference (V) = Current (A) x Resistance (Ω)

( V = I x R )

Question 17

How do you find power in terms potential difference?

Answer 17

Power (W) = Potential difference (V) x Current (A)

P = V x I

Question 18

How do you find power in terms of current?

Answer 18

Power (W) = (Current)2 (A) x Resistance (Ω)

( P = I x R )

Question 19

How do you find energy transferred in terms of transfer red power?

Answer 19

Energy transferred (J) = Power (W) x Time (s)

( E = P x t )

Question 20

How do you find energy transferred in terms of transferred charge flow?

Answer 20

Energy transferred (J) = Charge flow (C) x Potential difference (v)

( E = Q x V )

Question 21

How do you find density?

Answer 21

Density (Kg/m3) = Mass (kg) / Volume (m3)

( ρ = m / V )