Rates Involving two or more variables (1 Viewer)

[Nekoccino]

Hurro~! ^^
I'm stuck with this Maths in focus question, Exercise 6.2
Q30
A rectangular block of ice with a square base has a height half the side of the base. As it melts, the volume of the block of ice is decreasing at the rate of 12 cm3s-1. Find the rate at which its surface area will be decreasing when the side of its base is 2.1 cm.

Please help and thanks in advance ~ ^^

 

[integral95]

Hurro~! ^^
I'm stuck with this Maths in focus question, Exercise 6.2
Q30
A rectangular block of ice with a square base has a height half the side of the base. As it melts, the volume of the block of ice is decreasing at the rate of 12 cm3s-1. Find the rate at which its surface area will be decreasing when the side of its base is 2.1 cm.

Please help and thanks in advance ~ ^^

inb4 enigma

Anyways, let the side of the base be s

and A be the surface area of the block

you'll need







The rest is finding the derivative and subbing into the first equation i gave you.

 

[enigma_1]

did sum1 mention maths in focus

my blood boils

OP are you aware that MIF is a terrible textbook?

 

[photastic]

But the question is pretty good tbh.

 

[Nekoccino]

I don't like maths in focus, but well, that question was an alright one, thanks everyone ^^
I made a minor mistake

 

[gaste]

did sum1 mention maths in focus

my blood boils

OP are you aware that MIF is a terrible textbook?

It's not a terrible book for developing foundation..

 

[gaste]

I don't like maths in focus, but well, that question was an alright one, thanks everyone ^^
I made a minor mistake

Hey! Nothing is wrong with MIF! As long as you understand what is needed, then it's all good!

By the way, once you have exhausted the hardest questions or seem to have demolished the book, it is recommended that you seek other textbooks that have questions to challenge you. That is, to give evolution to your understanding of a particular concept!