Answer:
Step-by-step explanation:
The area of a circle is given b
A=πr²
Then,
dA/dr= 2πr
Also give that,
dr/dt=30m/hr, r=100m
We want to find dA/dt
dA/dt=dA/dr×dr/dt
dA/dt= 2πr × 30
dA/dt= 2 ×π ×100×30
dA/dt=18849.56m²/s.
The rate of the area is 18849.56m²/s