Question

pls help me do if u don't know how to do pls don't answer or else u will be reported I need it under 25min thank u​

Answer 1

see explanation

Explanation:

given that V is directly proportional to u and inversely proportional to f , then the equation relating them is

V =
`(ku)/(f)` ← k is the constant of proportion

(a)

to find k use the condition when u = 1 and f = 3 , V =
`(1)/(6)` , then

`(1)/(6)` =
`(k)/(3)` ( cross- multiply )

6k = 3 ( divide both sides by 6 )

k =
`(3)/(6)` =
`(1)/(2)`

V =
`(u)/(2f)` ← equation of proportion

(b)

when f = 4 and V = 1
`(1)/(4)` =
`(5)/(4)` , then

`(5)/(4)` =
`(u)/(2(4))` =
`(u)/(8)` ( cross- multiply )

4u = 40 ( divide both sides by 4 )

u = 10