6. 1/2 base x height
- area of a triangle
- area of a quadrilateral
7. V / t
- acceleration
- pressure
8. (useful energy output / total energy output) x 100%
- efficiency
- pressure
9. frequency x wavelength
- wavespeed
- area of a triangle
10. total distance / total time
- average speed
- efficiency
11. 1 / time period
- frequency
- work done
12. current x resistance
- voltage
- charge
13. force x perpendicular distance form the pivot
- moment
- potential energy
14. force / area
- pressure
- work done
15. thinking distance + breaking distance
- stopping distance
- average speed
16. base x height
- area of a quadrilateral
- area of a triangle
17. current x time
- charge
- orbital speed
18. weight x height
- potential energy
- efficiency
19. work done / time taken
- power
- force
20. current x voltage
- power
- frequency
