Answer:
Step-by-step explanation:
D. 64 square units
Answer:
(i) The name of the part of the circle, OQ is a radius
(ii) The radius of the sector QOR is 21 cm
Step-by-step explanation:
The given figure is a sector of the circle O
∵ Any sector of a circle formed from 2 radii and an arc
∴ OQ is a radius
(i) The name of the part of the circle, OQ is a radius
The rule of the length of an arc of a circle is L =
× 2 π r, where
- α is the angle of the sector
- r is the radius of the circle
∵ The length of the arc QR is 22 cm
∴ L = 22
∵ The measure of the angle of the arc is 60°
∴ α = 60°
∵ π = 
→ Substitute them in the rule above
∵ 22 =
× 2 ×
× r
∴ 22 =
r
→ Divide both sides by 
∴ 21 = r
(ii) The radius of the sector QOR is 21 cm
Answer:
18432 km/h
Step-by-step explanation:
It is given that a sound wave travels through iron at a rate of 5120 m/s.
We know that
1 km = 1000 m
1 hour = 60 minutes
1 minutes = 60 second
Using these conversions we get
1 m = 0.001 km
1 hour = 3600 second


Therefore, the sound wave travels through iron at a rate of 18432 km/h.
Answer:
c
Step-by-step explanation: