Above, a 16-ft ladder leans against a wall. You can move the blue point along the ground
to see how the movement of the top of the ladder relates to the movement of the bottom
of the ladder. To animate smoothly, click the blue dot then press and hold the
arrow keys.
Explore
- If the bottom of the ladder moves away from the wall at a constant rate,
how would you describe the movement of the top of the ladder?
- If `x` is increasing, is `dh/dt` positive or negative? Here `x` is the distance
from the bottom of the wall to the bottom of the ladder, `h` is the distance
from the bottom of the wall to the top of the ladder, and these quantities change
as a function of time, `t`.
- Suppose the bottom of the ladder is `5` ft from the wall at time `t = 0` and it slides
away from the wall at a constant rate of `3` ft/s. Find the velocity of the top
of the ladder at time `t = 1`.
- Suppose the top of the ladder slides down at a constant rate of `4` ft/s.
Calculate `dx/dt` when `h = 12`.