(Solved): Question 7 ( 10 Marks) Vraag 7 (10 Punte) The block with mass m is suspended (i.e. motion is in the ...
Question 7 ( 10 Marks) Vraag 7 (10 Punte) The block with mass
mis suspended (i.e. motion is in the vertical plane) from a spring, with spring constant
k, and is free to move between the two smooth walls. Space for rough work is provided on the next page. It will not be graded. Die blok met massa
mhang aan 'n veer met vecrkonstante
k(m.a.w. beweging is in die vertikale vlak) en is vry om tussen die twee gladde wande te beweeg. Rofiverkspasie word op die volgende bladsy voorsien. Dit sal nie nagesien word nie. (a) For
k=4(N)/(m),m=15kg, and
F=0(no driving force), for which value of the damping coefficient
cis the system critically damped? (b) For
k=25(N)/(m),m=100kg.c=0(no damping), and a driving force
F=7sin\omega _(0)t, for which value of the driving frequency
\omega _(0)would resonance occur? (c) For
k=100(N)/(m),m=5kg,c=0,(no damping), and
F=7sin8t: i) What is the period of the steady state vibrations? ii) What is the amplitude (in meter) of the steady state vibrations? (d) For
k=8(N)/(m),m=15kg,c=30N*(s)/(m). and
F=0(no driving force), what type of damped motion occurs? (a) Vir
k=4(N)/(m),m=15kgen
F=0(geen dryfkrag), vir watter waarde van die dempingskoëffisiënt
csal die stelsel krities gedemp wees? (b) Vir
k=25(N)/(m),m=100kg,c=0(geen demping), en 'n dryfkrag
F=7sin\omega _(0)t, vir watter waarde van die dwangfrekwensie
\omega _(0)sal resonansie voorkom? [2] (c) Vir
k=100(N)/(m),m=5kg,c=0(geen demping), en
F=7sin8t: i) Wat is die periode van die standhoudende vibrasies? ii) Wat is die amplitude (in meter) van die standhoudende vibrasies? (d) Vir
k=8(N)/(m),m=15kg,c=30N*(s)/(n)en
F=0(geen dryfkrag), watter tip. gedempte beweging vind plaas? [2]
