A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 seconds, the angular velocity decreases to 200 rev/min. Assuming the angular acceleration is constant, how many revolutions does the blade undergo during this time

20 revolutions

Explanation:

Using,

Ф = (ω+ω')t/2 Equation 1

Where Ф = amount of revolution the blade undergo, ω = initial angular velocity  of the blade, ω' = Final angular velocity of the blade, t = time after switch off.

Given: ω = 1000 rev/min, ω' = 200 rev/min, t = 2 seconds = (2/60) min = 1/30 min

Substitute into equation 1

Ф = (1000+200)(1/30)/2

Ф = 1200/(30×2)

Ф = 1200/60

Ф = 20 rev.

Hence the blade undergoes 20 revolutions

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it