Question 180824
Joint variation is represented by y=kxz (y varies jointly as x and z).  So if the force varies jointly as the area and the square of the velocity, we have that
{{{f=kav^2}}}
So, if f=75, a=500 and v=50, we have that
{{{75=k(500)(50^2)}}}
{{{75=k(1250000)
{{{k=0.00006}}}
So, if v=75 and a=10, then
{{{f=0.00006(10)(75^2)}}}
{{{f=3.375}}}
So the force is 3.375 lbs.