Equations

Question 1

Density

Answer 1

Mass / Volume

Question 2

Distance

Answer 2

Speed / time

Question 3

Acceleration

Answer 3

Change in speed / time

Question 4

Kinetic energy

Answer 4

0.5 x mass x (speed)^2

Question 5

Force

Answer 5

Mass x acceleration

Question 6

Momentum

Answer 6

Mass x velocity

Question 7

Work done

Answer 7

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

Question 8

Power 🕐

Answer 8

Work done / time

Question 9

Force exerted by a spring

Answer 9

Extension x spring constant

Question 10

Gravity force

Answer 10

Mass x gravitational field strength , g

Question 11

In a gravity field : potential energy

Answer 11

Mass x height x gravitational field strength , g

Question 12

Pressure

Answer 12

Force normal to a surface / area of that surface

Question 13

Moment of a force

Answer 13

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

Question 14

Charge flow

Answer 14

Current x time

Question 15

Potential difference

Answer 15

Current x resistance

Question 16

Energy transferred

Answer 16

Charge x potential difference

Question 17

Power 💡

Answer 17

Potential difference x current

Question 18

Power 🔌

Answer 18

(Current)^2 x resistance

Question 19

Energy transferred

Answer 19

Power x time

Question 20

Wave speed

Answer 20

Frequency x wavelength

Question 21

Efficiency

Answer 21

Useful output energy transfer / input energy transfer