### Unit 2 Test Review

```AP Physics 1 Unit 2 Review
What you should know when all is said and done
1. Distinguish between…
a.
b.
c.
d.
qualitative & quantitative.
distance & displacement.
speed & velocity.
average & instantaneous velocity.
2. Given a x vs. t graph, you should be able to:
a. describe the motion of the object (starting position, direction of motion, velocity)
b. draw the corresponding v vs. t graph
c. draw the corresponding a vs. t graph
d. draw a motion map for the object (including v and a vectors)
e. determine the average velocity (slope of secant)
f. determine the instantaneous velocity of the object at a given time (slope of tangent)
3. Given a v vs. t graph, you should be able to:
a. describe the motion of the object (starting velocity, direction of motion, acceleration)
b. draw the corresponding x vs. t graph
c. draw the corresponding a vs. t graph
d. draw a motion map for the object (including v and a vectors)
e. write a mathematical model (equation) to describe the motion
f. determine the acceleration (slope)
g. determine the displacement for a given time interval (area)
4. You should be able to determine the instantaneous velocity of an object in three ways:
a. determining the slope of the tangent to an x vs. t graph at a given point.
b. using the mathematical model v = at + v0
c. using the mathematical model v2 = 2aΔx + v02
5. You should be able to determine the displacement of an object in three ways:
a. finding the area under a v vs. t curve
b. using the mathematical model Δx = ½ at2 + v0t
c. using the mathematical model v2 = 2aΔx + v02
6. You should be able to determine the acceleration of an object in five ways:
a. finding the slope of a v vs. t graph
b. using the mathematical model a 
v
t
c. rearranging the mathematical model Δx = ½ at2 + v0t
d. rearranging the mathematical model v = at + v0
e. rearranging the mathematical model v2 = 2aΔx + v02
7. Use the acceleration due to gravity (ag) to find…for an object in free fall.
a. the time,
b. the displacement,
c. velocity (initial or final),
d. or any other variable solved for in your worksheet questions.
Also, you might try:
http://www.physicsclassroom.com/Class/1DKin/
http://www.walter-fendt.de/ph14e/acceleration.htm
PART B: Assooiafing Morion wifh gÿaph8 oÿ Posifion VSo Time
For each description of a physical situation, (a) identify which of the graphs below could
represent the motion of the object; and (b) indicate how the variable x relates to the
physical situation. In some cases, you should specify which direction is positive before
choosing a graph. (Note: For some situations, more than one graph is acceptable.)
x
t
x
0
0
X
x
t
X
0
t
X
F
o
t
0
t
0
t
E3. A ball is dropped from a height of i meter above the floor. Take the origin to
be at the level of the floor.
Answer: For ÿup" chosen to be the positive direction, graph D would represent
the motion of the ball.
Nxplanation: The variable x represents the height of the ball above the floor.
This height starts at 1 meter at t = Os and diminishes to zero at a later time.
Graph E is incorrect because the graph does not start at x = l m. Graph B
qualitatively describes the motion since the graph starts at positive x and
diminishes.
A marble is rolled at constant speed along a horizontal surface toward the origin.
The
marble is released at a distance of 1 meter away from the origin.
A block sits at rest on a table i meter above the floor. Take the origin to be the level of
the floor.
A ball is dropped from a height of 2 meters above the floor.
Take the origin to be the
point from which the ball is released.
A ball is rolled along a horizontal surface. The ball strikes a wall and rebounds toward
the origin.
B5. A car is parked on a steep hill.
```