Answer:u=1/16
Step-by-step explanation:
u is inversely proportional to v^2
u=k× 1/v^2
u=k/v^2
When U=4/9 when v=3
4/9=k×1/3^2
4/9=k×1/9
4/9=k/9
Cross multiply
4×9=k×9
36=9k
Divide both sides by 9
36/9=9k/9
4=k
When v= 8, u=?
u=k/v^2
Recall k=4
u=4/8^2
u=4/64
u=1/16