1) The height of a helicopter above the ground is given by h =
3.25t3, where h is in meters and t is in seconds. After 1.85 s, the
helicopter releases a small mailbag. How long after its release
does the mailbag reach the ground?
2) As soon as a traffic light turns green, a car speeds up from
rest to 52.0 mi/h with constant acceleration 9.50 mi/h-s. In the
adjoining bike lane, a cyclist speeds up from rest to 16.0 mi/h
with constant acceleration 14.00 mi/h-s. Each vehicle maintains
constant velocity after reaching its cruising speed.
(a) For what time interval is the bicycle ahead of the car?
(b) By what maximum distance does the bicycle lead the car?
3)A rock is dropped from rest into a well. Mary counted 16
seconds before she heard the sound of the splash. The well is not
really 16 seconds deep.
(a) The sound of the splash is actually heard 2.5 s after the
rock is released from rest. How far below the top of the well is
the surface of the water? The speed of sound in air (at the ambient
temperature) is 336 m/s.