Question

If two forces are in ratio 5 is to 7 and on two areas 4 is to 5 then what is the ratio of their pressure

Answer 1

we know,

pressure is the force act on per unit cross section area . e.g pressure = force/area

P1/P2 =F1.A2/F2.A1

=(F1/F2)(A2/A1)

given,

F1/F2 = 5:7

A1/A2 =4:5 so, A2/A1 =5:4

hence,

P1/P2 =(5/7)(5/4) =25/28

hence pressure ratio = 25 :28