Math 1501

Sept. 23, 1999
Tom Morley
Name: ____________________________

Don't Panic

Open Book and Notes. You have 40 minutes. Carefully explain your proceedures and answers

Problem 1 (10 points)


You are videotaping the peachtree bicycle road race. You are 50 ft from
the (middle of the) road. You are following a bicycle going at 25 miles
per hour down Peachtree. (Note: 25 miles per hour is 36 .67 feet per second.)
How fast is the camera angle changing when the bicycle is right in from of you?
How fast 1 second later? Express answers in radians per second.
.

[Graphics:indexgr2.gif][Graphics:indexgr1.gif]
[Graphics:indexgr2.gif][Graphics:indexgr3.gif]
Calculations

[Graphics:indexgr2.gif][Graphics:indexgr4.gif]
[Graphics:indexgr2.gif][Graphics:indexgr5.gif]
[Graphics:indexgr2.gif][Graphics:indexgr6.gif]

You can convert everything to feet or everything to miles.
Careful.

[Graphics:indexgr2.gif][Graphics:indexgr7.gif]
[Graphics:indexgr2.gif][Graphics:indexgr8.gif]

[Graphics:indexgr2.gif][Graphics:indexgr9.gif]
[Graphics:indexgr2.gif][Graphics:indexgr10.gif]

[Graphics:indexgr2.gif][Graphics:indexgr11.gif]
[Graphics:indexgr2.gif][Graphics:indexgr12.gif]

[Graphics:indexgr2.gif][Graphics:indexgr13.gif]
[Graphics:indexgr2.gif][Graphics:indexgr14.gif]

When the bicycle is straight ahead, cos[&thgr;] = 1.

[Graphics:indexgr2.gif][Graphics:indexgr15.gif]
[Graphics:indexgr2.gif][Graphics:indexgr16.gif]

Radias per second.

[Graphics:indexgr2.gif][Graphics:indexgr17.gif]

[Graphics:indexgr2.gif][Graphics:indexgr18.gif]
[Graphics:indexgr2.gif][Graphics:indexgr19.gif]

[Graphics:indexgr2.gif][Graphics:indexgr20.gif]
[Graphics:indexgr2.gif][Graphics:indexgr21.gif]

Problem 2 (10 Points)

A plane is flying with a constant speed of 300 km/hr at a height of 4 km. The plane flies over a ground radar installation. One half hour later, how fast is the distance
from the plane to the radar installation changing?

Answer

[Graphics:indexgr2.gif][Graphics:indexgr22.gif]
[Graphics:indexgr2.gif][Graphics:indexgr23.gif]

[Graphics:indexgr2.gif][Graphics:indexgr24.gif]
[Graphics:indexgr2.gif][Graphics:indexgr25.gif]

[Graphics:indexgr2.gif][Graphics:indexgr26.gif]
[Graphics:indexgr2.gif][Graphics:indexgr27.gif]

[Graphics:indexgr2.gif][Graphics:indexgr28.gif]
[Graphics:indexgr2.gif][Graphics:indexgr29.gif]

[Graphics:indexgr2.gif][Graphics:indexgr30.gif]
[Graphics:indexgr2.gif][Graphics:indexgr31.gif]
[Graphics:indexgr2.gif][Graphics:indexgr32.gif]
[Graphics:indexgr2.gif][Graphics:indexgr33.gif]
[Graphics:indexgr2.gif][Graphics:indexgr34.gif]