First Examination
Physics 103
23 September 1980
#1. To change 60 km/hr to ft/sec, the appropriate conversion
is
Answer:
#2. A vector R, as
shown in the sketch, has a magnitude of 10 m and makes an angle of 30o
with the +x-axis. The vector R
is most closely equal to
Answer:
#3. We are given the vectors
A = 3 i
+ 4 j
B = i
- 2 j
+ 2 k
Let q be the angle between
A
and B. Which of these statements is true?
Answer:
#4. A car travels 6 km EAST for 4 minutes, then 8
km NORTH for 6 minutes. The average velocity (in
km/hr) is most nearly equal to
Answer:
#5. The displacement vs time curve for an object is given
below. The corresponding velocity vs time curve would look like:
Answer:
#6. A rocket blasts off vertically from rest. A graph of its
vertical velocity (m/sec) versus time (sec) is shown. The average
acceleration of the rocket during the first 5 seconds of flight is most nearly
equal to
Answer:
#7. A truck starts from rest and moves with constant acceleration.
At time t1 it has a speed of 10 m/sec, and at a
later time t2 it has a speed of 15 m/sec. During
the time interval (t1, t2) it has
moved 100 m. Note: This is one-dimensional motion. The
time interval between t1 and t2
is
Answer:
#8. In Problem #7, the acceleration of the truck is
Answer:
#9. An "el" train accelerates uniformly from rest to 60
mi/hr in 15 seconds. It maintains that constant velocity
for 45 seconds, and then decelerates to rest in 10 seconds. The
total distance traveled is most nearly equal to
Answer:
#10. An object is dropped from rest from a bridge 36 feet above a
lake. It falls with a uniform acceleration of 32 ft/sec2
until it hits the water; then it sinks with its constant
"splashdown" velocity. Three seconds after it was
dropped, the object reaches the bottom of the lake. What is the depth
of the lake?
Answer:
#11. A ball is thrown vertically straight up (in the +y direction). At
the position of its maximum altitude it is true that
Answer:
#12. A football player kicks a ball 200 feet (ground to ground) from its initial position. If
the angle of the initial velocity with respect to the ground is 300, the
magnitude
of the initial velocity is most nearly equal to
Answer
#13. A bullet is fired with an initial velocity v0 at a
target x feet away. the expression giving the vertical
displacement y from the initial line of sight (x-axis) is: Hint:
do not neglect gravity.
Answer
14. An airplane traveling at 150 m/sec at an angle of 30o below
the horizontal, drops a package from a height of 1000 m. The horizontal
displacement of the package when it hits the ground, relative to the drop
point, is approximately
Answer:
#15. A car travels around a circular track at a fixed speed of 50 ft/sec
in a time of 20 seconds. The radial acceleration experienced by the
car is
Answer: