Answer:
I believe its 15
Step-by-step explanation:
Answer:
0.3
Step-by-step explanation:
By definition: 30% = 30/100 = 0.3
As you said it was dropped so in that case I'll take 78.4 meters as the height..
we know that
h = ut + 0.5*g*t(sqr)
t(sqr) = 78.4/(0.5*9.8) [g = 9.8 ms-2]
t = √16
t = 4
So it'd take 4 seconds
Answer:

Step-by-step explanation:
For this case the solution flows at a rate of 2L/min and leaves at 1L/min. So then we can conclude the volume is given by 
Since the initial volume is 10 L and the volume increase at a rate of 1L/min.
For this case we can define A as the concentration for the salt in the container. And for this case we can set up the following differential equation:

Because at the begin we have a concentration of 8 gr/L and would be decreasing at a rate of 
So then we can reorder the differential equation like this:

We find the solution using the integration factor:

And then the solution would be given by:

And if we simplify this we got:

And after do the integral we got:

And using the initial condition t=0 A= 20 we have this:


So then we have this function for the solution of A:

And now replacinf t= 40 we got:

Answer:
I thinks this is the answer
198.2673 round up remember, Hope this helps ️️