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CH 4 Mixed Review 46,50,53,55,56,59,61,&63. CH 4 Mixed Review 46,50,53,55,56,59,61,&63. F N. F A. W. F || F A. cos30 =. 24.5 F A. cos30 =. 46. m = 5 W = 49 W = 42.4 W || = 24.5. Equations from Diagram: W || = F || F N = F + W . F || F . W || - PowerPoint PPT Presentation
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46
30°
W
W||
W
FA
F||
F
FN Equations from Diagram:
W|| = F||
FN = F + W
m = 5
W = 49
W= 42.4
W|| = 24.5
cos30 = F||
FA
cos30 = 24.5
FA
Same as W||
FA = 28.3 N
FN = F + W
FN = 14.2 + 42.4
FN = 56.6 N
Now that you know FA = 28.3 , you can use sin30 to get F
50
T
W
T - W = FNET
T - 5(9.8) = 5(3)
T = 64 N
53FN
W
Ff
FN = W
Ff = FNET
Find d:
vi = 7
vf = 0
d = ?
a =
Find a:Find Ff:
same as FNET FNET = m a
32.3 = 65.8a
a = .491
Ff = FN
Ff = .05(645)
Ff = 32.3.491
vf2 = vi
2 + 2ad
02 = 72 + 2(.491)d
d = 49.9 m
55
30°
W
W||
W
FN
Ff W|| - Ff = FNET
FN = W
m = 3
W=29.4
W=25.5
W||= 14.7
A.
vi =0
d = 2
t = 1.5
a = ?
d = vit + ½ at2
2 = ½ a(1.5)2
a = 1.78 m/s2
B.
W|| - Ff = FNET
14.7 – Ff = 3(1.78)
Ff = 9.36 N Ff = FN
9.36 = (25.5)
= .367
C. Already found this !
9.36 N
D. vf2 = vi
2 + 2ad
vf2 = 2(1.78)2
vf = 2.67 m/s
56 Ff
W
W – Ff = FNET
Find vf :Find a :Find FNET :
vi = 0
vf = ?
d = 25
a =
FNET = maW – Ff = FNET
75(9.8) – 95 = FNET
FNET = 640
640 = 75a
a = 8.53 8.53
vf2 = vi
2 + 2ad
vf2 = 2(8.53)(25)
vf = 20.7 m/s
59
35°
W
W||
W
FN
FA
Ff W|| = Ff
W + FA = FN
m = 3
W = 29.4
W= 24.1
W|| = 16.9
Find FA :
W + FA = FN
Find FN :
Ff = FN
16.9 = .300FN
FN = 56.3
24.1 + FA = 56.3
FA = 32.2 N
61
°
W
W||
W
FN
FA W|| = FA
W = FN
sin = W||
W
sin = 300
12200
Same as FA
= 1.4°
63
2 34
180
A. Whole:
W
FN
FA
FNET = ma
180 = 9a
a = 20 m/s2 For ALL blocks
B.
Resultant force is NET force
FNET = ma= 2(20)
= 40 N
For m1
FNET = ma= 3(20)
= 60 N
For m2
FNET = ma= 4(20)
= 80 N
For m3
C. Between m1 and m2:
W
FN
Ffrom m1
FNET = ma= 7(20)
= 140 N
D. Between m2 and m3 :
80 N…..it is the NET force on m3