21-106: Topics in Pre-Calculus
Homework: Week #4
- Due at the start of class on Monday, September 13...
Read:
- Review your notes.
-
Exercises:
- A boat is pulled into a dock by a rope attached to the bow of the boat
and passing through a pulley on the dock that is 1.3m higher than the bow of
the boat. The rope is being pulled in at a rate of 2m/s and at time t=0,
there is 15m of rope between the boat and the pulley. (Assume the rope always
forms a straight line.) Write a function d(t) that gives the distance of the
boat from the dock after t seconds have elapsed.
- Two streets intersect at a 110 degree angle. There is a monument on one
of the streets, 7mi from the intersection. If a car leaves the intersection
at time t=0 and travels 30mph along the other street, write a function that
gives the distance x(t) between the car and the monument at time t.
- An extendable ladder may vary between 16 and 24 feet in length. At time
t=0 the ladder is standing vertically against a wall, and fully retracted to
16ft. At that time the bottom of the ladder is pulled away from the wall at a
rate of 3ft/s and simultaneously, the ladder is extended at a rate of 1ft/s.
- At what time will the top of the ladder touch the ground.
- Write a function h(t) that gives the height of the top of the ladder
after t seconds.
- What is the average speed of the top of the ladder during the first second?
During the last second?
- Due at the start of class on Wednesday, September 15...
Read:
- Review your notes.
Exercises:
- The problems from Monday's assignment, which was not properly linked.
- The additional problem from Monday's lecture.
- Due at the start of class on Friday, September 17...
Study for your exam!