Helppppppppp?

Question

Answer 1

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Volume =pih(r_outer^2 - r_inner^2) 

V  = 6pi( r_outer^2 - (3)^2 )

V = 6pi(r_outer^2 -9) 

dV/dr  =12pi(r_outer)  

dV/dt = dV/dr * dr/dt  

so when r_outer = 4.5 cm 

dV/dr = 12pi(4.5) = 54pi  cm^3/ cm 

dr/dt =   0.04  cm/hour 

dV/dt =  54pi cm^3/cm * 0.04 cm/hour =  2.16pi cm^3/hour

dV/dt =  6.785840132

 dV/dt = 6.786  cm^3/hour 

Answer 2

you haven't even tried this problem !!!...appears to be a ' ring ' of ice with

volume of V = 6π ( r² - 3²)........dV / dt = 6π ( 2 r dr/dt  )...you finish