Semestertoets test 1

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Semestertoets / test 1
1. 'n Skyf roteer uit rus om sy sentrale as en
versnel teen konstante hoekversnelling. Op een
tydstip roteer dit teen 10 rev/s. Na nog 60
voltooide omwentelinge is die hoeksnelheid 15
rev/s. Bereken die hoekversnelling. A disk
rotates about its central axis starting from rest
and accelerates with constant angular
acceleration.. At one time it is rotating at 10
rev/s. After 60 more complete revolutions, its
angular speed is 15 rev/s. Determine the angular
acceleration. (3)
Bereken die tyd benodig om die 60 omwentelinge te
voltooi. Determine the time required to complete
the 60 revolutions. (3)
Bereken die tyd benodig om die 10 rev/s
hoeksnelheid te bereik. Determine the time
required to attain the 10 rev/s angular
speed. (2)
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Bereken die aantal omwentelinge vanuit rus totdat
die skyf die 10 rev/s hoeksnelheid bereik
het. Determine the number of revolutions from
rest until the disk has attained the 10 rev/s
angular speed. (2)
Wat is die rotasie kinetiese energie? What is the
kinetic energy of rotation? (3)
3
Skryf 'n uitdrukking neer vir die
traagheidsmoment van die stelsel na impak. Write
down an expression for the moment of inertia of
the system after impact. (2)
4
Skryf 'n uitdrukking neer vir die hoek momentum
van die stelsel net na impak. Write down an
expression for the angular momentum of the system
immediately after impact. (2)
As die hoeksnelheid van die staaf en koeël
onmiddelik na impak 10 rad/s is, wat is die
groote van die koeël se snelheid net voor
botsing? If the angular velocity immediately
after impact is 10 rad/s, what is the magnitude
if the bullet's velocity just before impact?
(3)
5
Skryf 'n uitdrukking neer vir die sommasie van
die kragte in die y-rigting. Write down an
expression for the summation of the forces in the
y-direction. (1)
Wat is die statiese wrywings koëffisiënt tussen
die 10.0 kg blok en die oppervlak waarop dit
rus? What is the coefficient of static friction
between the 10.0 kg block and the surface on
which it rests? (4)
6
Skryf n uitdrukking neer vir die kinetiese
energie van die sisteem as die silinder deur die
ekwilibrium posisie gaan nadat dit uit rus
losgelaat is. Write down an expression for the
kinetic energy when the cylinder goes through the
equilibrium position after it is released from
rest. (2)
Deur te aanvaar dat die silinder nie gly nie,
skryf hierdie uitdrukking as n funksie van die
massa M en snelheid v van die silinder alleen. By
assuming that the cylinder does not slip, write
this expression as a function of the mass M and
the velocity v of the cylinder only. (3)
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Bepaal nou die translasie kinetiese energie van
die sisteem by die ewewigs punt. Determine now
the translational kinetic energy of the sistem at
the equilibruim point. (3)
Bepaal die rotasie kinetiese energie van die
sisteem by die ewewigs punt. Determine the
rotational kinetic energy of the sistem at the
equilibruim point. (2)
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6. By n sekere hawe veroorsaak die getye dat
die water oppervlak styg en daal met n afstand d
oor n periode van 12.5 h. Skryf n uitdrukking
neer vir die verplasing x as n funksie van d,
die tyd t en die periode T. At a certain harbor,
the tides causes the ocean surface to rise and
fall a distance d in simple harmonic motion, with
a period of 12.5 h. Write down an expression for
the displacemant x as a function of d, the time t
and the period T. (1)
Skryf x nou as slegs n funksie van d as die
water met d/4 vanaf die maksimum posisie
daal. Write down x as a function of d only if the
water fall a distance d/4 from its maximum
position. (1)
Hoe lank neem dit die water om hierdie afstand te
daal? How long does it take the water to fall
this distance? (2)
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7. n Golf met n golflengte van 0.3 m beweeg
langs n draad wat 300 m lank is en n totale
massa van 15 kg het. Bepaal die lineêre digtheid
van die draad. A wave whose wavelength is 0.3 m
is traveling down a 300 m long wire whose total
mass is 15 kg. Determine the linear density of
the wire. (2)
As die draad onder n spanning van 1000 N is, wat
sal die snelheid van die golf wees? If the wire
is under a tension of 1000 N, what is the
velocity of the wave? (2)
Wat is die frekwensie van die golf? What is the
frequency of the wave? (2)
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8. Dit word geadverteer dat n hoë kwaliteit
luidspreker, by volle volume, frekwensies tussen
30 Hz en 18000 Hz met uniforme intensiteit van ?3
dB kan voortbring. (oor hierdie frekwensie gebied
sal die intensiteitvlak met nie meer as 3 dB van
die gemiddelde verskil). Met watter faktor sal
die intensiteit verander vir n maksimum
intensiteitvlak verandering van 3 dB? A high
quality loudspeaker is advertised to reproduce,
at full volume, frequencies from 30 Hz to 18000
Hz with uniform intensity ?3 dB.(over this
frequensy range , the intensity level does not
vary by more than 3 dB) By what factor does the
the intensity change for the maximum intensity
level change of 3 dB? (4)
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9. Die vibrasie van n 600 Hz stemvurk veroorsaak
staande golwe in n snaar wat aan beide kante vas
is. Die golfspoed vir die snaar is 400 m/s. Die
staande golf het vier loops en n amplitude van
2 mm. Wat is die lengte van die snaar? Vibrations
from a 600 Hz tuning fork sets up standing waves
in a string clamped at both sides. The wave
speed for the string is 400 m/s. The standing
wave has four loops and an amplitude of 2 mm.
What is the length of the string?(3)
Bepaal die golf getal k van die
ossilasie. Determine the wave number k of the
oscillation. (3)
Bepaal die hoek frekwensie van die
ossilasie. Determine the angular frequency of the
oscillation. (2)
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Skryf n vergelyking neer vir die verplasing van
die snaar as n funksie van posisie en tyd. Write
an equation for the displacement of the string as
a function of position and time. (2)
10. In n toets, vlieg 'n subsoniese veg
vliegtuig op 'n hoogte van 100 m. Die
klankintensiteit op die grond as die vleigtuig
oor beweeg is 150 dB. Op watter hoogte moet die
vliegtuig vlieg sodat die grond geraas nie meer
as 120 dB, die pyndrumpel, is nie? In a test, a
subsonic jet flies overhead at an altitude of 100
m. The sound intensity on the ground as the jet
passes overhead is 150 dB. At which altitude
must the jet fly so that the ground noise is no
greater than 120 dB, the threshold of pain? (6)
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11. n Besondere orrelpyp kan resoneer by 264
Hz, 352 Hz en 440 Hz, maar nie by enige
frekwensies tussen in nie. Is dit n oop of toe
pyp? A particular organ pipe can resonate at 264
Hz, 352 Hz and 440 Hz, but not at any frequencies
in between. Is it an open or closed pipe? (3)
Wat is die fundamentele frekwensie? What is the
fundamental frequency? (1)
Watter harmonikas word gehoor? Which harmonics
are heard? (3)
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12. Ultra-klankgolwe word gebruik om die
vloeisnelheid van bloed te bepaal. Veronderstel
n toestel straal klank teen 500 kHz uit en dat
die snelheid van klank in die menslike liggaam
1540 m/s is. Wat is die frekwensie van die klank
wat die bloedselle bereik as bloed normaalweg
teen 2.0 cm/s in groot are beweeg direk na die
klank bron toe? Ultrasound waves are used to
measure blood flow speeds. Suppose a device emits
sound at 500 kHz, and the speed of sound in human
tissue is taken to be 1540 m/s. What is the
frequency of the sound that reaches the blood
cells if blood is normally flowing in large
arteries at 2.0 cm/s directly towards the sound
source? (3)
As die klank golwe nou van die bloedselle af
terug gereflekteer word, wat is die frekwensie
van die gereflekteerde klank golwe wat deur n
waarnemer, wat langs die aanvanklike bron staan,
waargeneem word? If the sound waves is reflected
from the blood cells, what is the frequency of
the reflected sound waves detected by an observer
standing next to the original source? (3)
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Wat is die frekwensie van die swewinge wat deur
die waarnemer gehoor sal word? What is the
frequency of the beats that such an observer will
hear? (2)
13. n Vlêrmuis, wat stil sit, stuur
ultrasoniese klankgolwe met n frekwensie van 50
000 Hz uit en ontvang dit terug as dit
gereflekteer word vanaf n voorwerp wat radiaal
weg beweeg teen 25.0 m/s. Wat is die frekwensie
wat n waarnemer by die bewegende voorwerp
waarneem? A bat at rest sends out ultrasonic
sound waves at 50 000 Hz and which are reflected
from an object moving radially away from it at
25.0 m/s. What is the frequency detected by an
observer at the moving object? (3)
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Wat is die frekwensie van die klank wat deur die
vlêrmuis waargeneem word? What is the frequency
of the sound detected by the bat? (3)
14. Op 'n sekere tydstip is die posisie vektor,
in meter, van 'n 0.25 kg voorwerp r 2.0i
2.0k. Op daardie tydstip, is die snelheid, in
meter per sekonde, v -5.0i 5.0k, en die krag,
in newton, wat op die voorwerp inwerk F 4.0j.
Wat is die hoekmomentum van die voorwerp om die
oorsprong? At a certain time, the position vector
in meter of a 0.25 kg object is r 2.0i 2.0k.
At that instant, its velocity in meters per
second is v -5.0i 5.0k, and the force in
newton acting on it is F 4.0j. What is the
angular momentum of the object about the
origin? (3)
Watter draaimoment werk op die voorwerp in? What
torque acts on the body? (2)