1. Warm-up: one red book per table
Page 45 Read Figure 3-5
compare to Figure 3-6 page 46

2. 3.1 Section Review
# for a stamp

3. Warm-up:
Graph the acceleration and determine if it is speeding up or slowing down (deceleration) or
constant (straight line). Stamped.
Graph 1: Graph 2:
The object dropped from The bug moved
6m at 1 s to m at 3s
5m at 2 s to m at 6s
4m at 3s to m at 9s
3m at 5s to
2m at 8s

5. The distance between each dot represents the body’s change in position during that time interval.
Large distances between adjacent dots indicate that the body was moving fast during that time interval.
Small distances between adjacent dots indicate that the body was moving slow during that time interval.
A constant distance between dots indicates that the body is moving with constant velocity and not accelerating.

6. d = vi (t) + .5 (a)(t2) Vavg = d
Vf 2 = vi (a)(d)
Vf = vi + a (t) a = Δv Δt
d = vi + vf 2t
when vi is not when vi is 0
vf = vi + g ∆t vf = g ∆t
vf2 = vi2 + 2 g d vf2 = 2 g d
d = vi ∆t g ∆t d = 0.5 g ∆t2
d = ( vi + vf ) ∆t d = ( vf ) ∆t

7. A fast sprinter can cover 100m in 10s flat.
(a). What is the average speed of the sprinter?
Vavg = d
t = 10 m/s
(b) What would his time be for the mile (1610m)
If he could keep up the sprint pace?
Vavg = d t = d m
t v 10m/s

8. 2. An object moves with a constant velocity of
15m/s.
How far will it travel in 2.0s?
Vavg = d d = v (t)
t d = 15m/s (2.0s)
d = 30m
(b) If the time is doubled, how far will it travel?
d = 15m/s(4.0s)
d = 60m

9. 3. An object initially at rest, moves with a constant
acceleration of 10m/s2. How far will it travel in
2.0s
d = vi (t) + .5 (a) (t2)
d = 0(2) + .5 (10) (22)
(40)
d = 20m

10. 3. An object initially at rest, moves with a constant acceleration of 10m/s2. How far will it travel in (b) 4.0s
d = vi (t) + .5 (a)(t2)
0 (4) + .5 (10m/s2) (16)
(160)
d = 80m
If the vi is 4m/s for 2 seconds (d) 4.0 seconds
d = 4m/s (2s) + .5 (10m/s2) (4s) d = 4(4) + .5 (10)(16)
(40)
d = 28m d = 96 m

11. 4.
A pitcher throws a baseball with a velocity of
132 ft/s (90mph) toward home plate that is
approximately 60 ft away. Assuming the horizontal
velocity of the ball remains constant, how long does
it take to reach the plate?
Vavg = d t = d s = 60
t v

12. The speed of light is 3.0 x 108 m/s. Assume that
the length of a “standard room” is 20m (22 yards).
How many “room lengths” can light travel in 6.5s?
Vavg = d d = x 108 (6.5s) d = 1.95 x 109m
t m
1.95 x 109m
20m = x 107 room length

13. A bunny rabbit on a jet ski increases its speed
from 25m/s to 35 m/s in a distance of 250m.
Find the time required and the acceleration.
Vavg = d t = d s = m
t v m/s
a = ∆v m/s a = 1.2 ms2
∆t s

14. 8. A reindeer running increases its velocity uniformly
from 16m/s to 32m/s in 10 sec.
What is its acceleration?
a = ∆v m/s = 1.6m/s2
∆t s
Vavg = vi + vf Vavg = 24m/s
d = vi (t) + .5 (a) (t2)
16 (10) (1.6) (100)
(160)
d = 240m

15. Free fall A ball is thrown straight up in the air.
The moment it leaves the hand of the person
throwing it, it accelerates at a rate of -9.8 m/s2.
If the ball travels 19.2 m up, then what was its initial velocity?
2. How long does it take to reach the top of its
trajectory? (19.2 m)

16. Givens: formula:
d = 19.2m vf = vi2 + 2ad
vf = = vi 2 + 2(-9.8)(19.2)
a = 9.8m/s = vi2 + ( )
Vi? How do we isolate vi2?
vi2 = √376.32

17. t = 1.98s Givens: formula: d-=19.2 m vf = vi + a(t)
vf = 0 m/s = (-9.8)t
vi = m/s =
a = 9.8 m/s = -9.8(t)
How do we isolate time?
t = 1.98s

18. Page 6 in blue book
A common flea can jump a distance of 33 cm. Suppose a flea makes five jumps of this length in the northwest direction. If the flea’s northward displacement is 88 cm, what is the flea’s westward displacement?
Scale 1cm = 33cm
Vector is pointing north of west
What is one half of 90°?

19. The longest snake ever found was a python 10. 0 m long
The longest snake ever found was a python 10.0 m long. If the snake were stretched along a coordinate system on the ground from the origin making a 60° angle with the positive x-axis. Find the x and y coordinates of the vector the snake makes.

20. A South-African sharp-nosed frog set a record for a triple jump by traveling a distance of 10.3 m. Suppose the frog starts from the origin of a
coordinate system and lands at m
relative to the y-axis,
what angle does the vector of displacement
(frog’s leap) make with the y-axis? And
what is the x-component of the frog’s leap?