This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: PHSX 114 Exam #2, code number 1 2 l. (10 points) The vector E1 of magnitude 7.7 has an angle of 218.7° with respect to the
positive x—axis (see ﬁgure). Find the x and y component of this vector. Ax=7~1* CoyWT
Z —' 6.0 c) %:7.0ff4.sjﬁ A721] ksmwgqo d) A=—6.4i—7.9j 218.?0 e) 21:43:29.2] 234.95 A7: Y <
‘1 A7.
A‘ ~ *4 V 2. (10 points) Two forces 1?] = —(3.0N)f + (4.0N)j' and 17; = (6.0N)f + (7.0N)} are
applied to a box. The magnitude of the total force on the box is: a 0. 1:: *4 ‘5.
b) i4? v =F1+Fz
: r Fﬂlgm‘i'FZXE‘EN‘F :BN‘
6) 1.2.2N F7, :FW+ET1.4N+7N: l\.l\5.
FnJFFQTFVL: Chill "2 H‘LILN' 3. (10 points) A car of mass 800 kg made a sudden stop in 5.00 seconds from its original
velocity of 20.0 m/s in the positive X—direction. Assumin'gJa constant force was applied to stop the car, this force is: P ‘z’ 7 20‘ D M
a) 1900 N, along the positive X—direction g j \J a: —~—_——é : arty/2.
D b) 3200 N, along the negative Xdjrection 5 5 ‘
c) 520 N, along the positive x—direction F : m CN :1 3 00 k5 x 4‘. M 1 d) 160 N, along the negative X—direction /3 A
e) None of the above :1 a"; DO N 0408 __ . 4. (10 points) A force F acts on mass M for a time interval T, giving it a ﬁnal speed v. If
the same force acts for the same time on a different mass 0.5M, what would be the ﬁnal speed of the smaller mass? _
fo—Ei , m :L: god
a 4v ‘ 0.5M '
b) 2v Ul:alT_
c v
d) M212 _~ —~ __ " 1‘
e) U412 D1—all H PHSX 114 Exam #2, code number 1 3 5. (10 points) Three blocks of mass 3m, 2m, and m are connected by strings and pulled
with constant acceleration a. What is the ratio between T1 and T3? aiTl/iii m g QnJ'mggmj o\ ,2 émcm. C)T1/T3:1/3 ._
d)T1/T3=l/6 T77 “ m 0" 6) T1 /T3 =1/2 T
1 3m 6. (10 points) A person of 100 kg mass is standing on a scale inside a moving elevator.
What is his apparent weight showing on the scale if the elevator is moving with an
upward acceleration of 4.9 mfsz? W N"VY1 :m&.
a) 980N % 15 b) 490N \ TCK‘ W:m(é+&) _ 578N lei) 1960N I ROMS "(l'glékoU 2—3.
I: [470 M» 7. (10 points) A child throws a ball horizontally with an initial speed of 15 m/s. The ball
leaves her hand 1.2 m above the ground. What horizontal distance does the ball travel? a) 0.27m x yii‘lM: i512. b 1.8m 2\@ x.“ m
“M \x t : .i’iii“: :oa‘iss,
e) ism 3 ﬁrm gar all . $3 in ct FOL/moi
L—lSMSKQQ—EZlLFm LS .
8. (10 points) An airplane is traveling horizontally at constant speed. A package is 
dropped from the airplane. One second later a second package is dropped. Assuming air
resistance effects can be neglected, which of the following is an accurate statement? a) The vertical distance between the two packages will remain constant as they
fall. b) The horizontal distance between the two packages will increase as they fall. 0) The second package will hit the ground more than one second after the ﬁrst hits.
he vertical distance between the two packages will steadily increase as they
fall. 6) The horizontal distance between the two packages will decrease as they fall. PHSX 114 Exam #2, code number 1 4 9. (10 points) A projectile is launched with an initial velocity of 60 mfs at an angle of 30°
above the horizontal. What is its horizontal range over level ground? ‘2.
a 180m M02 SCWZQ @O%)’gl‘w 600
0) 150m 6 2 M
d)230m Chg} 1.
e)400m /LS l1.3\8“.lm 10. (10 points) In the ﬁgure, the kinetic coefﬁcient of the table is #13025. What is the
acceleration a of the system (Box A + string + Box B)? ) 7.1 m/s2 H : T. m if m 4.0kng
1:) 3.3rr1/s2 Angjq AR 1:234/ 7 c) 1_4m/Sz E) : m5 3  l :. m& 0\ g 2 ~~ 2/...
W2) Aﬁ'Eb ;‘ Millik"';::','""""“it” @b‘mt‘ﬂl93=(mstma0\ W3 3 : “‘“L
F. i .7 N: W.  j ‘2.qu
a: W3; (6% w I?) W‘sWW5 é Fﬁr’tN MK Extra credit arablem (10 Qaintsg: A 1400 kg car is traveling up a 15" slope at 28 m/s. The driver slams on the brakes and
skids to a halt. If the coefﬁcient of friction is pk=0.79, what distance does the cagravﬁ ‘0 7< before it stops? YA \J /
iqu oilch‘i'Fo‘h . 5 7
a) 155m J >O~ 9%"
b) 79m mﬂCosls * FM :0 J 0
0) 52m 8 "o
d) 5111] 0 Five ijosl’D m3 F1”:MKFN \. m X —~0LireC/‘i‘j¢rv\_ m6 SinlSo +th5<losi5° 2 Wok. SO alé‘mlb—O ‘t‘ 0.79ACOEAS ‘ﬁx‘ligm/sz :(O' O” ...
View
Full Document
 Spring '08
 DAVIS
 Velocity, 30°, 0 j, FnJFFQTFVL, 7.9j

Click to edit the document details