Question

A helicopter hovers 40 ft above the ground. Then the helicopter climbs at a rate of 21 ft/s. How do you write a rule that represents the helicopter's height `h` above the ground as a function of time `t`?

Answer 1

`h = 21 t + 40`

Explanation:

If the helicopter climbs at a (constant) rate of `21 ft"/"s` then its distance at time `t` (relative to its starting point at height `40 ft` is given by:

`"speed"="distance"/"time" => "distance" = "speed" xx "time"`

Hence,

`\ \ \ h_("relative to height of 40 ft") = 21 * t`

`:. h_("relative to height of 0 ft") = 21 * t + 40`

`:. h = 21 t + 40`