GCSE equations

Question 1

Kinetic energy=

Answer 1

½ x mass x velocity²

Ek=½mv²

Question 2

GPE=

Answer 2

mass x gravitationa field strength x height

Ep=mgh

Question 3

(energy) power=

Answer 3

work done/time taken energy transferred/time taken

P=w/t P=e/t

Question 4

efficiency=

Answer 4

useful energy output/ total energy input

useful power output/ total power input

Question 5

density=

Answer 5

mass/volume

p=m/v

Question 6

charge flow=

Answer 6

current x time

Q=It

Question 7

Potential difference=

Answer 7

current x resistance

V=IR

Question 8

(electricity) power=

Answer 8

current x potential difference (current)² x resistance

P=IV P=I²R

Question 9

(electricity) energy transferred=

Answer 9

power x time charge flow x potential difference
E=Pt E=QV

Question 10

wave speed=

Answer 10

frequency x wavelength

Question 11

Weight=

Answer 11

mass x gravitational field strength

W=mg

Question 12

Work done=

Answer 12

force x distance (moved along the line of action of the force)

W=Fs

Question 13

Force=

Answer 13

spring constant x extention

F=Ke

Question 14

Moment of a force=

Answer 14

force x distance (normal to the direction of the force)

M=Fd

Question 15

Pressure=

Answer 15

force normal to a surface/ area of that surface

p=F/A

Question 16

distance travelled=

Answer 16

speed x time

s=vt

Question 17

acceleration=

Answer 17

change in velocity/ time taken final velocity-initial velocity time taken

𝑎 = Δ𝑣 /𝑡 𝑣 − 𝑢 / t

Question 18

resultant force=

Answer 18

mass x acceleration

𝐹 = 𝑚a

Question 19

momentum

Answer 19

mass x velocity

𝑝 = 𝑚v

Question 20

Magnification=

Answer 20

image height/ object height