A fan belt with radius 8cm rotates 30 revolutions in 2 minutes. How far will a point on the belt travel in 10 seconds

Question

It’s a trig function question

Answer 1

I take it that the rotation is 15 rpm (rev./min).

The Circumference is 2(pi)(8 cm) = 16pi cm--that's distance the point travels in one revolution;

15 revolution in one minute means total travel distance is 15•2•pi•8 cm = 240pi cm.

But in 10 seconds, 1/6 of a minute, the point will travel 40pi centimeters, or about 125.66 cm.

Answer 2

C=∏d

C=3.14159*16

C=50.26544 cm in 1 revolution

2 minutes=120 seconds

30 revolutions in 120 seconds

10/120=1/12

(1/12)*30=30/12=2.5 revolutions

2.5*50.26544=125.6636 cm

or,...

30 revs in 120 seconds

1 rev in 4 seconds

10/4=2.5 revs

2.5*50.26544=125.6636 cm again