Motion in one dimension, Section Quiz Acceleeration:
1 d, 2 b, 3 c, 4 c, 5a, 6 d, 7b, 8d,
9 CD, DE, EF, FG. The displacement of the jogger with a constant acceleration is equal to the average velocity
during a time interval multiplied by the time interval. Because time intervals are equal, the displacements are in the
same order as decreasing average velocities. They decrease in order CD, DE, EF, FG.
10 x = vi t =+ 1/2 a x t squared.
(.25 m/s) (3.0 s) + .(40 m/s/s) (3.0 s)squared / 2 = 2.6
m
Graph Skills: Displacement & Velocity
1. yes, from t1 to t4 & t6 to t7
2. yes, from t4 to t5
3. greater than
4. greater than
5. yes, trom 0 to t1 & from t5 to t6
6. yes, from t1 to t2, and t2 to t4, from t4 to t5, and t6 to t7.
7. -5.0 m ( or 5.0 to the west where it started)
Mixed Review continued...
3. A speed up + and +
B speed up + and +
C constant velocity + and 0
D slowing down + and -
E slowing down + and -
4a
1 4.9m 0m/s -9.81 m/s/s
2 0 m -9.8 m/s -9.81 m/s/s
3. -14.7m -19.6 m/s -9.81 m/s/s
4. -39.2m -29.4m/s -9.81m/s/s
4b. 1 second
4c. 2 seconds
Significant Figures Rules:
Use these in your calculations:
1. All nonzero numbers are significant (1,2,3,4,...)
2. Zeros:
Significant: zeros in between other numbers are significant
trailing zeros in a number that has a decimal point (1.3. 200.00
Not Significant
trailing zeros when there is no decimal point (i.e. 1000)
zeros in front of a number are not, they are place holders
for example ( 0.00201)
Exace numbers hav4e unlimited significant figures
numbers that were determined by counting
numbers by definition.
Calculations
nultiplication and division
answer has the same significant number as the smallest
number
of sig figs used to produce the product/quotient
adding and subtracting
answer should have the least number of precise digits as
the
least precise number used to derive the total/difference
When you make measurements
Record
all of the certain numbers plus the one uncertain number
Chapter 2 Text
Practice A Answers:
1. 2.0 km to the east
2. 3.1 km 3. 680 m to the north
4. 3.00 h
5. 0.43 h
6a) 6.4 h 6b)
77 km/h to the south
Practice B Answers:
1. 2.2 s
2. 2.0 s 3 . 5.4 s 4. -3.5 x 10-3
m/s2
5a) 1.4 m/s 5b) 3.1 m/s
Practice C Answers:
1. 21 m 2. 18.8
m 3. 9.1 s 4. 24 m/s
Practice D Answers:
1. 9.8 m/s; 29 m
2. 19.3 m/s; 59.0 m 3. -7.5 m/s; 19 m
4. 2.5 s ; 32 m
Practice E Answers:
1. +2.51 M/S
2a) +21 m/s 2b) + 16 m/s 2c) +13 m/s
3a. 16 m/s
3b. 7.0 s 4. 7.4 m 5, +2.3 m/s2
6. 88 m
Practice F Answers:
1a. -42 m/s 1b. 11 s 2a. 22.1
m/s 2b. 2.25 s 3a. 8.0 m/s
3b. 1.63 s
4. 1.8 m
Chapter 2 Review
1. 5.0 m; +5.0 m 2. the slope of
the line at each point
3. t1; negative: t2 positiive: t3; positive: t4; negative;
t5: zero
4a. 0 to t1; tt1 to t2; t3 to t4; t4 to t5 4b)
t1 to t2; t2 to t3; t3 to t4
5. The duck's displacement must also be zero
6. The time interval is always positive because time
can only move in one
direction (forward)
7. 10.1km to the east
8. 4.22 x 10 to the 1st km
9a) +70.0 m 9b) +140.0 m
9c) +14 m/s 9d) +28 m/s
10a) 53.5 km/h 10b) 91.0 km
11. 0.2 km west of the flagpole
12. 0.00 m/s/s 13a) slope is
zero 13b) slope is + 13c) slope is -
13d) skioe is - 13e) slope is +
14. yes, a car traveling eastward and slowing down has a westward
ac-
celeration.
15a) left half of top photo, bottom photo
15b) right half of top photo
15c) middle photo 16 4.0 s
17. 0.0 m/s/s; +1.36 m/s/s; +0.680 m/s/s
18. 2.2 x 10 2nd power
19. 110 m 20. +8.6 m/s 21a)
-15 m/s 21b) -38 m
22. + 1.5 m/s; 32 m
23. 17.5 m 24a). 11 m/s 24b) 52 s
25. 0.99 m/s
26a) the ball's velocity decreases, becomes zero at
its maximum
altitude,
then increases in the negative direction.
26b) At maximum altitude, the ball's velocity is zero
26c) -9.81 m/s/s
26d) -9.81 m/s/s 26e) The ball's
acceleration remains constant
27) For each ball, the velocity can be analyzed as the distance
between
images, and the acceleration can
be seen by comparing the distances
both balls are accelerating:
they start with approximately the same
acceleration, but the smaller
ball's acceleration gradually decreases
because of air resistance.
28) The two pins have the same acceleration (-9.81
m/s/s)
29a) yes; 29b) yes; 29c) yes
30. -39.6 m/s 31. 3.94 s
32) 0.60 s 33. 1.51
h 34a) 0.20 s 34b) 0.06 s and 0.34 s
34c) Answers vary slightly but should be close to these:
t = 0.05 s, v
= 2 m/s
t = 0.10 s, v
= 1 m/s
t = 0.15 s, v =
0.5 m/s
t = 0.20 s, v
= 0 m/s
34d) Answers will vary but should be near -10 m/s/s
35a) 2.00 min 35b) 1.00 min
35c) 2.00 min
36a) 3.0 s 36b)
-24.5 m/s for each 36c) 23.6 m 37 931 m
38a) 0.05 h 38b) 81 km
39) -2.6 m/s; 31 m
40a) -24 m/s 40b) 31 m
41. 1.6 s 42a) 24.6 s 42b) 738 m
43) 5s; 85s; +60 m/s
44a) 6100 m 44b) 9 s
45) -1.5 x 10 third m/s2 46a) 2.33 s
46b) -32.9 m/s
47a) 3.40 s 47b) -9.2 m/s
47c) -31.4 m/s; -33 m/s
48a) 310 m 48b) 8.5 s
48c) 16.4 s 49a) 4.6 s after stock car return
49b) 38 m 49c) +17 m/s (stock car);
+21 m/s (race car)
50a) 13 s 50b) -2.9 m/s/s
50c) 12 s 51) 4.44 m/s
