4. The blades on a fan have a frequency of 15 Hz.
a) How many cycles do the blades complete in five minutes?
b) What is the period for the fan blades?
c) How long would it take for the fan blades to complete 100 revolutions?

a) 4500 cycles.

b) (1/15) s = 0.0667 s

c) (20/3) s = 6.667 s

Explanation:

The blades on a fan have a frequency of 15 Hz

This means the number of cycles completed per second = 15

a) How many cycles do the blades complete in five minutes?

5 mins contains 5 × 60 seconds, that is, 300 seconds.

The fan completes 15 cycles in 1 second

In 300 seconds, it will complete

15 × 300 cycles = 4500 cycles.

b) What is the period for the fan blades?

Period = (1/frequency)

= (1/15) = 0.0667 second per cycle.

c) How long would it take for the fan blades to complete 100 revolutions?

This means how long would the fan complete 1 cycle as 1 rev = 1 complete cycle.

The fan complete 1 cycle in (1/15) second

The fan will complete 100 cycles in (100×1/15) =

(20/3) s = 6.667 s

Hope this Helps!!!

answer: the correct answer id option(d).

explanation:

snell's law refraction:

the angle of refraction =

the angle of incidence =

refractive index of air = = 1

refractive index of glycerol = 1.47

from the given options, the most closest answer to 63.72° is 65° of option (d).