Question

F

is inversely proportional to
√
g
.
When
f
=
15
,
g
=
144

Work out
g
when
f
=
90

Answer 1

4

Explanation:

The proportional relationship can be described by the equation ...

`f=(k)/(√(g))`

We can fill in the given values to find k:

15 = k/√144 = k/12

15·12 = k = 180 . . . . . . multiply by 12

Then for f = 90, we have ...

90 = 180/√g

1/2 = 1/√g . . . divide by 180; next multiply by 2√g and square both sides

g = 2² = 4 . . . . the value of g when f=90