The distanceãd in kilometres to the horizon can be estimated using the formula d = 13h,where h is the height above ground level, in metres, of the observer.

Question

The distanceãd in kilometres to the horizon can be estimated using the formula d = 13h,where h is the height above ground level, in metres, of the observer.
(a)
Use the formula to find the distance to the horizon for an observer on the London Eye, 135m above ground.
(b)
Rearrange the formula to make h the subject

PsyDAG · Answer

(a) Substitute 135 for h and solve for d. (b) Divide both sides by 13.

The distance�ãd in kilometres to the horizon can be estimated using the formula d = 13h,where h is the height above ground level, in metres, of the observer.