BCLN PHYSICS 11 - Rev Sept/16
65.
Maty is attempting to drag her 32.6-kg Shepard across the wooden floor by applying a horizontal
force. What force must she apply to move the dog with a constant speed of 0.95 m/s? The
coefficient of friction between the dog and the floor is 0.72.
66. A 20 kg block rests on a frictionless table. A cord attached to the block extends horizontally to a
pulley at the edge of the table. A 10 kg mass hangs at the end of the cord.
a. Clearly draw and label the force vectors acting on each object.
b. Calculate the acceleration of the block and mass.
c.
Calculate the tension in the cord.
ANSWERS
1.
2.
3.
4.
5.
6.
7.
8.
9.
1.0 kg m/s
3.0 m/s
- 3.6 m/s
3.4 m/s
0.88 m/s
129kg m/s or 129 Ns, 25.8 N
a) -13.1 kgm/s, or -13.1 Ns (Ball reverses direction.), b) - 1.31 x 104 N
43 m/s
2
a) 1.2 x 10 J, b) 0J
10. 375 J
11. 4.32 x 106 J
12. (a) 6.9 x 103 W, (b) 9.3 HP
13. The ramp reduces effort force at the expense of effort distance, which increases. The ramp does not save
you work!
14. 0.17 m (or 17 cm)
15. 320 m
16. 20 kJ
17. 3Ek
18. 323oC
19. Water gives off 10 times as much heat.
20. Efficiency = 93%
21. Efficiency = 92%
o
22. 200 J/kg/C
23. Ek = ½ mv2 , Doubling mass will double kinetic energy, but doubling speed will quadruple kinetic energy.
24. 3.8 x 103 J
25. Without considering friction, ½mv2 = mgh.
v2
(25 m /s)2
=
= 32 m
2g
2(9.8 m/s2 )
With friction, the vertical height will be less.
26. 2.0 A
27. 72 V
28. 16V, 180W
h=
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BCLN PHYSICS 11 - Rev Sept/16
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
0.50 Ω
1.5 V
8.1 Ω
1600x
83%
diagram
0.645 m
5.0 x 106 m, or 5000 km!
(a) 0.20 Hz, (b) 5.0 s
(a) refraction, (b) frequency, (c) Wave speed is reduced by about one half.
change in frequency of a wave caused by a source moving in relation to the receiver
335 m/s
(a) D, (b) C
42.
r = 21 , The beam will leave the glass at 35 .
43. 9.
ic = 41.1
44. 10. n = 1/sin45 = 1.41
45. 1.4
8
46. 2.06 x 10 m/s
47.
48.
49.
50.
51.
52.
53.
54.
Place the filament between f and 2f.
1.7 m (real image)
2.0 m
(a)
Do is greater than 2f.
(b)
Do is between f and 2f.
(c)
Do = 2f
(d)
Do is much less than f.
Inverted, diminished, real image forms between C and F.
22.5 cm
Inverted, enlarged, real image forms beyond C
Di = - 3.75 cm (virtual image)
3.75cm
Hi
Di
= 0.375
=
=
Ho
Do
10.00cm
(Image is diminished and right side up.) Hi = 1.9 cm.
Image is on the same side of the lens as object.
55. vavg. = 5.13 x 10-3 m/s
56.
57.
58.
59.
60.
a. t = 0.625 h, b. v = 133 km/h
a-5, b-3, c-1, d-2, e-3
v = 104.5 m/s
a. d = 28.2 m, b. v = -23.5 m/s, c. a = +325 m/s2
a. Total Area = 15 m
b.
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BCLN PHYSICS 11 - Rev Sept/16
61.
62.
63.
64.
65.
66.
113 km/h
a. 3.1 m/s, 38° east of north, b. 16s, c. 30m
mass = 86kg, weight = 140N
8.37m/s2 down
230N
a. refer to tutorials, b. 3.27 m/s2, c. 65.3N
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