CH 1,2,3
SAMPLE
PROBLEM TYPE
QUESTIONS
1] Let East represent the positive x
axis and North
the positive y axis. A constant wind with a speed
of 10.0 km/hr is
blowing due
NE. You have a model airplane that flies at 30.0 km/hr in level flight
in
still
air. You start its engine and release it in the direction due NW. What
will be
the displacement of
the airplane relative to your position after it
flies for
10.0 minutes?
ANSW: 5.26 km @ 117 degrees
2] A turtle is observed to travel at the rate of 0.50 cm/s.
Assuming
he travels on a straight line,
how long (in hours) will
it take him to travel 1.6 km?
ANSW: 89 hrs
3] A train travels uphill from station A to station B in 6.0
hours. It makes the return trip downhill
in 4.0 hours. If its average
speed for the entire trip (uphill and downhill) was 48 km/hr,
determine the speed for
each part of the trip. { i.e., give speed in going from A to B
and speed in going from
B to A}
ANSW: A to B is 40 km/hr , B to A is 60
km/hr
4] A ball is thrown vertically downward from a height of 55.0
m above the ground. It reaches the
ground 2.60 s later. What
is the velocity of the ball just before striking the ground?
( a = -9.80 m/s2 for
gravity)
ANSW: - 33.9 m/s
2] Assume the motion of a kicked football follows that of a
projectile above
the surface of the earth.
The ball is kicked from directly in
front of
the goalpost and hits the crossbar. If the ball was kicked
from 20.0 m
away
with a velocity of 15.0 m/s at an angle of 45 degrees to the
horizontal, what
is
the height of the crossbar?
ANSW: 2.53 m
5] A) An object moves with constant
speed
from position 0 m to position +5 m during an
interval of 2 seconds. It
remains at position +5 m for one second, then it returns at constant
speed to position 0 m during
an interval of 2 seconds.
FIRST: make a sketch of position versus time for the above object.
SECOND: describe (a calculation is not necessary) the average velocity
for the entire
motion of the object.
ANSW: average velocity is zero
(B) An object has
an
initial velocity of + 2 m/s. It is then subjected to a constant
acceleration
of - 0.5 m/s2 for many many seconds. Qualitatively
describe
what happens to the velocity
of the object during this acceleration.
ANSW: Object behaves just like a ball tossed
upward against gravity
ANSW: 30.6 m
B) A second rock is then
thrown straight down from the same bridge and reaches the water
in only 1.25 seconds. What was the velocity of the rock just before
striking
the water?
ANSW: -30.7 m/s
2] A) It is known that 1.00 m3 of
aluminum has a mass of 2.70 x 103 kg. A square plate of
aluminum that is 1.00 cm thick has a mass of 75.0 gm. What is the
length
of one side
of the square plate in centimeters?
ANSW: 5.27 cm
B) Two square plates of a
certain metal have the same mass. Plate A has a thickness of
0.50 cm while plate B has a thickness of 0.25 cm. What is the ratio of
the length of
one side of plate A to the length of one side of plate B?
ANSW: 0.71
3] You’re worried about your physics exam and pace back and
forth
in your room. You pace
at the rate of one step
per second. First you go right (positive) for 4 steps, then left
(negative)
for 5 steps, then right
for 6 steps, and finally left for 3 steps. Graph this motion and
determine
the average velocity in
steps/sec.
ANSW: 0.1 steps/sec
4] A car starts with an initial velocity of 8.0 m/s and
travels
for 5.0 sec with a uniform
acceleration of +1.5 m/s2
. The driver then applies the brakes, causing a uniform
negative acceleration of
-2.0 m/s2 for 2.5 sec. What is the velocity of the car at
the
end of the braking period?
ANSW:
+10.5 m/s
1] A plane is flying directly over ETSU at the moment
you begin
this exam. The pilot is heading due
West at 500 km/hr, but he is flying
in a 60
km/hr wind that is blowing due South. Where will the
plane be (with
respect to
ETSU) when the exam period is over 80 minutes from
now.
ANSW: 672 km @ 6.8 degrees SW
2] Assume the flight of a baseball follows that of a
projectile above
the surface of the Earth. You are
the batter and hit a low pitched
baseball
that lands at the top of an outfield wall 85.0 meters away.
If you gave
the
baseball a velocity of 30.0 m/s at an angle of 40.0 degrees to the
horizontal,
what
is the velocity of the ball when it strikes the top
of the wall? (ignore the initial
height of the ball
when you hit
it)
ANSW: 28.6 m/s @ 36.5 degrees below horizontal
CH 1,2,3 SAMPLE MULTIPLE CHOICE TYPE
QUESTIONS
1] Suppose that two quantities, A and B, have different
dimensions. Determine which
of the following arithmetic operations could be
physically meaningful.
a) A + B
b) B -
A c) A -
B d) A/B
2] Which of the following expressions is dimensionally
consistent with an expression for
acceleration (units of distance divided by time
squared)? In each case, x is a distance,
t is time, and v is velocity.
a) v /t2
b) v/x2
c) v2
/t d) v2
/x
3] An x versus t graph is drawn for a ball moving in
one direction. The graph starts at the
origin, increases with a positive slope for five
seconds, and then levels off to a zero slope for
2 seconds. We can be sure that
a) the speed is decreasing
during the first 5 seconds
b) the acceleration is constant
throughout the complete motion
c) the speed is zero between t=5
sec and t=7 sec
d) the displacement is zero
throughout the motion
e) more than one of the above is
true
4] A ball is thrown straight up.
For which situation are both the instantaneous velocity and the
acceleration zero?
a) on the way up
b) at the top of the flight
path
c) on the way down
d) none of the above
5] Ball A weighs twice as much as ball B. A
is dropped straight down from the roof of a building and
at the same time B is thrown off the building
horizontally at a high speed. Neglect air resistance and
determine which statement below is true.
a) A hits the ground before B
b) B hits the ground before A
c) They both hit at the same time
d) there is not enough
information to determine an answer
6] A 6 km displacement and an 8 km displacement
are at right angles to each other. The resultant displacement
is found to be 10 km due east. Which of the
following is a possible set of directions for the 6 km and 8 km
displacements?
a) 6 km is to the NE and
8 km to the SE
b) 6 km is to the NW and 8 km to
the SW
c) 6 km is to the NE and 8 km to
the NW
d) 6 km is to the SW and 8 km to
the SE
Answers:
1) d
2) d
3) c
4) d
5) c
6) a