Ch 3: 3-3 Clarifying v-t, a-t, d-t Relationships
1.
2.
Vel (m/s)
20
b
Label the x-axis in increments of 10 s.
Label the y-axis in increments of 5 s.
Q: Does the car ever change direction?
How do you know?
c
15
a
10
d
5
e
A
B
C
D
E
Time (s)
Complete the table below using the above diagram.
List the motion as:
speeding up, slowing down, constant, or at rest
List the direction of the velocity as:
+, -, or 0 (0 = no velocity)
List the direction of the acceleration as: +, -, or 0 (0 = no acceleration)
Then, describe what is going on comparatively
Time
Interval
A
B
C
D
E
Motion
Direction Direction
of v
of a
Comparative assessment
Make a d – t graph and an a – t graph.
Consider the following formulas / information:
 df = di + vit + ½ a t2
 d = ½ (vf + vi) t
 Areas under the curves*
 Slopes of the lines*
Q: What doesn’t the area under the curve tell you?
Q: When determining d – t intervals, what must you remember to do?
Q: What is so special about small – case letters a – e, as depicted above?
Q: What is a step function?
Q: What is a point of discontinuity?
Q: What is a right – hand and left – hand limit?
Draw a velocity versus time graph for a ball being tossed up in the air.
Why does it look like that? Explain each peak / trough / node (point) on the graph.
Draw the displacement versus time and acceleration versus time graphs. Explain each peak / trough /
node on the graph.
Think of an elevator
which you could have:
starting from rest, and then doin’ its thang. Describe the situations in
+a
-a
Complete the following sentences:
The slope of a velocity – time graph is the
___________________________________
The slope of a displacement – time graph is the
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