PHYS 201 TEST #1 9/16/09 Dr.
Holmes NAME:
DO ALL EIGHT PROBLEMS. THE WORTH OF EACH
PART OF EACH PROBLEM IS MARKED NEXT TO THE SLOT FOR THE ANSWER. SHOW YOUR WORK
FOR PARTIAL CREDIT.
1) a) What is your
height in feet and inches?
b) What is it in centimeters?
c) Express 32 meters/second in miles per hour:
71.7 mph
2) What angle
does the sun make when viewed from Triton, a moon of
a) in degrees: 0.018o;
b) in radians 3.11
x 10-4 radians;
c) in revolutions: 4.95
x 10-5 revs
d) As seen from the earth, the sun makes an angle of
0.5o. Would the sun appear to
make a smaller, the same, or bigger angle when viewed
from Jupiter compared to when it is viewed from the earth?
Smaller.
3) a) Convert the
following vector (18 cm, -27 cm) from rectangular to polar form:
(+32.5 cm, -56.3o)
b) Convert the following vector: (32
m, 154°) from polar to rectangular form:
(-28.76 m, -14.03 m)
4) Add the following three vectors and
express your answer in POLAR form:
A
= (24 m, 77°)
B
= (18 m, 133°)
C
= (16 m, 244°)
(26.16 m, 122.1o)
Draw a quick picture showing vectors A, B,
and C; also show the resultant vector and label it R:
5) A runner runs a 26.3 mile race (a
marathon) in 2 hours and 20 minutes even.
What is the person’s average velocity during
that time:
a) in m/s:
5.04 m/s.
b) in miles/hour:
11.29 mph.
c) At this average speed, how long would it
the runner to run 100 meters?
19.85
seconds
d) At
this average speed, how long would it take the runner to run one mile?
.0886 hours = 5 minutes 19 seconds.
6) To the right is a graph of v(t).
On the graphs below it, sketch x(t) and a(t) assuming
that xo< 0.
7) Given the following velocity data:
v(0 sec.) = 3
m/s
v(1 sec.) = 0
m/s
v(2 sec.) = -2
m/s
v(3 sec.) = 1
m/s
and given that xo = -5 meters;
a) What is the average acceleration between
t = 2 seconds and t = 3 seconds?
3 m/s2;
b) What is the position at t = 3 seconds?
-5 meters.
8) A ball is thrown straight up from the top of a
building. The building is 9 meters high.
The initial speed of the object is 32
m/s. Neglect air resistance.
a) How high up will the ball go (above the
ground)?
61.25 meters.
b) How long a time will it take for the ball to reach
that maximum height (from the time it was thrown)?
3.27 seconds.