CH 1,2  SAMPLE PROBLEM TYPE QUESTIONS

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

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

1]     A) A rock dropped from a bridge takes 2.50 seconds to hit the water below. How high is
the bridge?

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

CH 1,2  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