From V= 4/3*pi*r^3
<span>dV/dt = 4pi(r^2)dr/dt </span>
<span>so when dV/dt=30 and r = 19 </span>
<span>30 = 4pi(361)dr/dt </span>
<span>dr/dt = 30/[4pi(361)] </span>
<span>now in </span>
<span>A = 4pir^2 </span>
<span>dA/dt = 8pi(r)dr/dt </span>
<span>= 8pi(19)*30/[4pi(361)] </span>
<span>= you finish it.</span>
<span>HOPE THIS HELPS.
</span>
Answer:
50 + 100n
Step-by-step explanation:
The cost is the cost of the visit plus the cost of the cavities
50 + 100n where n is the number of cavities
Answer:
$19.25 for 7 bags of popcorn
Step-by-step explanation:
Answer:
The distance between them after 30 minutes is 6.5 km.
Step-by-step explanation:
Speed = 
Sarah's speed = 6 km/hr = 1.6667 m/s
Emily's speed = 10 km/hr = 2.7778 m/s
The measure of angle between their bearings = 
After 30 minutes (1800 seconds);
distance = speed x time
Sarah would have covered a distance = 1.6667 x 1800
= 3000 m
= 3 km
Emily would have covered a distance = 2.7778 x 1800
= 5000 m
= 5 km
The distance between them, a, can be determined by applying the cosine rule;
=
+
- 2bcCos A
=
+
-2(5000 x 3000) Cos 105
=
+
-2(5000 x 3000) x (-0.2588)
= 2.5 x
+ 9 x
+ 7764000
= 41764000
a = 
= 6462.5073
a = 6462.5 m
The distance between them after 30 minutes is 6.5 km.