<span>Since youc oncetrate all your force directly towards the moment arm it means that you push it at an angle of your force is directed to the left or the right and I bet that it must be 90</span> degrees to the bar. Obviuosly, if you are about to push it you will do it straight up but not in a zig zag way. In other words, it should be perpendicular to the arm because the<span> torque can be produced only if force is applied at a constant index (90).
Hope that helps! Regards.</span>
Answer:
The number A(t) of grams of salt in the tank at time t is 
Explanation:
Knowing

First we have to find the Rin and Rout
Rin = (concentration of the salt inflow) * (input rate of brine)
Rin = 1 g/L * 3 L/min = 3 g/L
Rout = (concentration of the salt outflow) * (output rate of brine)
Rout = (
) * (3 L/min) = 
Substituting this results
= 3 -
--> 
Thus, integration factors is

A(t) = 4 

Applying the initial conditions
A(0) = 40
c = 150 - 40 = 110
Now, substitute this result in the solution to get
