- #1
max0005
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Homework Statement
Dear All,
I am having problems understanding how to deal with related rates. The problem is the following:
A solid 400gm metal cube of size length 10cm expands uniformly when heated. If the length of its side expand at 0.5cm(hr), find the rate at which, after 5 hours, its volume will increase.
Homework Equations
The Attempt at a Solution
What I need to know is how the Volume will increase after five hours. Hence:
[tex]\frac{dV}{dt}[/tex]
As
[tex]V=S^3[/tex]
(V = Volume, S = Side, T = Time)
Then
[tex]\frac{dV}{dt} = 3L^2\frac{dS}{dt}[/tex]
Which is equal to
[tex]3L^2*0.5[/tex]
As to find the length of the sides:
[tex]f(S) = 10+0.5(T)[/tex]
Where T is time in hours. However, by substituting values I don't obtain the correct answer. Any help? :(