Which of the two examples below are, by standard, classified as high-energy impulsive sounds?

Watter twee van die voorbeelde hieronder, volgens standaard, word geklassifiseer as hoë-energie impulsiewe klanke?

NOTE: Although more than two answers may be selected, every wrong answer selected will be marked negatively. Only two below are correct.

At the fourth station the worker from Question 5 is situated 1.5 m from the point noise source. To reduce his total 8 hr noise exposure level to below 85 dB(A), what is the minimum distance away from the point source that he should be situated to complete his work?

By die vierde stasie voer die arbeider van Vraag 5 sy werk 1.5 m vanaf die puntgeraasbron uit. Indien sy 8 hr geraasblootstelling tot laer as 85 dB(A) beperk moet word, wat is die minimum afstand tussen die werkstasie en die puntbron?

A worker rotates through five working stations throughout his normal 8 hr work day as shown in the table below. Calculate the 8 h continuous rating level, , for the worker over his typical working day.

'n Werker roteer deur vyf werkstasies in 'n normale 8-ure werksdag soos aangetoon in die tabel hier onder. Bereken die 8 h kontinue klankdrukpeil, ,  vir 'n tipiese werksdag.

Calculate the continuous day/night noise rating level, , for the measurements in the Table below. Provide your answer in dB(A) and use 1 decimal place.

Bepaal die ekwivalente dag-nag geraasvlakpeil, , vir die metings in die Tabel hieronder. Jou antwoord moet in dB(A) gegee word. Gebruik 1 desimaal.

If the noise level in an environment halves, what would the resulting rise/reduction in dB be? 

Indien die geraasvlak in enige omgewing halfeer word, met hoeveel dB sal die geraasvlak styg/afneem?

What is the wavelength of a sound wave with a frequency of 500 Hz in dry air at 25°C? Provide your answer in [m] and use 2 decimal places.

Wat is die  golflengte van 'n klank met 'n frekwensie van 500 Hz in droe lug teen 25°C? Gee jou aantwoord in [m] en gebruik 2 desimale.

English

Assume (again) w(0,t) = w(L,t) = 0. Choose all possible mode shapes of a mooring line from the choices (A) - (H) below (negative marks for incorrect answers - do not guess).

Afrikaans

Aanvaar (weerheens) w(0,t) = w(L,t) = 0. Kies alle moontlike modusvorme van 'n kabel uit die keuses (A) - (H) hieronder (negatiewe punte vir verkeerde antwoorde - moenie raai nie).

English

The restoring force of a vibrating system is a force that acts to return the system to its equilibrium posiition. Identify the restoring force in the case of the mooring line.

Afrikaans

Die herstel-krag van 'n vibrerende stelsel is 'n krag wat die stelsel na sy ewewigsposisie laat terugkeer. Identifiseer die herstel-krag in die geval van die kabel.