Given:
In circle O, m∠R = 30.8°.
To find:
The m∠NOQ
Solution:
Central angle theorem: According to this theorem, the central angle is always twice of subtended angle on the same arc.
Angle NOQ and angle NRQ are on the same arc but ∠NOQ is the central angle and ∠NRQ is the subtended angle on the arc NQ.
Using central angle theorem, we get
Therefore, .
Answer:
v ≈ 8.5 km/h
Step-by-step explanation:
Since the diameter of the wheel is 3 m the radius will be r = 1.5 m.
Use the radius of the water wheel to find it's circumference C:
[set r = 1.5 m]
⇒
⇒ m
One revolution of the water wheel corresponds to meters so the angular velocity 15 rmp (revolutions per minute) corresponds to:
=
/min
Using this result, the speed of the river in kilometers per hour will be:
×
×
⇒
⇒ ≈
km/h