Trance music often relies on a DJ playing two records at the same time, The basi

Question

Trance music often relies on a DJ playing two records at the same time, The basic time signatures of the two records must match, however, otherwise the two records will play "out of synch" A DJ is playing an Armin van Buuren record on Turnatable A at a typical 33.3 rpm, while a Blank and Jones record rests motionless on Turntable B. At a given time, he turns on one record and turns off the other. If the Armin van Buuren record rotationally decelerates at one-fifth the rate of rotational acceleration of the Blank and Jones record, at what rotational speed will the two turntables match when they finally "synch"? If this process took 5.59 seconds, how many revolutions would the Armin van Buuren record sweep?

Explanation / Answer

Since the acceleration is 5 times the deceleration, B accelerates to 5/6 of the speed while A decelerates 1/6 of the speed (from full speed down to 5/6). Therefore, they match at 5/6(33.3) rpm. The average rotational speed of record A during this interval is 11/12 of 33.3 rpm (average of 1 x 33.3 and 5/6 x 33.3 = ((1 + 5/6)/2) x 33.3.). Divide that number by 60 to get the number of revolutions per second, then multiply by 5.59 seconds

= 0.508 rpm

= 2.840 rev

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.