Question

Please help with this calculus problem!



The mass, in kilograms of salt, in a brine solution as a solution of different concentrations is being poured into the container is
M = 20(1.5 + e^-0.02t), where t is the time in minutes.

i) Determine an equation for the rate of change of the mass of salt in the brine solution.

ii) After 5 mins, what is the rate of change of the mass of the salt in the solutions?

Answer 1

rate of change of M
= dM/dt
= d/dt [20(1.5 + e^-0.02t)]
== d/dt [20(1.5) + 20e^-0.02t)]
= 0+ 20(-0.02)e^-0.02t
= -0.4e^-0.02t

Answer 2

for ii, put t=5 into dM/dt == -0.4e^-0.02t
You'll get the rate of change of mass required :)

Answer 3

WOW! You know you're the best right?

Answer 4

NO, i'm not!!!

Answer 5

LOL, YES YOU ARE!!

Answer 6

So, I substitute 5 into -0.4e^-0.02t?

Answer 7

Yes, it should be like that...

Answer 8

yes he is

Answer 9

@JoBo Can you get the answer?

Answer 10

It asks for the rate of change right, so I get -0.03619(what are the units?)

Answer 11

kg/min?

Answer 12

Unit -> yes

Answer 13

answer -> should be yes

Answer 14

LOL, THANKS :)

Answer 15

Welcome :)

Answer 16

Im gonna post about 2 more, wanna help me on themÉ

Answer 17

I'll try ... I'm not sure if I know how to do it though

Answer 18

lol ok Im pretty sure youère smart enough :P

Answer 19

Not really :(

Answer 20

why are my question marks now ééés :(((

Answer 21

Hmmm.. I don't know too...

Answer 22

K im gonna post a new one