The drag force f on a boat varies jointly with the wet surface area a of the boat and the square of the speed s of the boat. a boat with a wet surface area of 50ft2 traveling at 7mph experiences a drag force of 98n . find the wet surface area of a boat traveling 7.5mph and experiencing a drag force of 135n .

Variation can be direct, inverse or joint.

The wet surface area is 60 square feet

The variation is given as:

Express as an equation

Make k the subject.

Rewrite as:

Where:

So, we have:

Make A2 the subject

Hence, the wet surface area is 60 square feet

Read more about variation at:

link

it should be a and d. lmk if i'm wrong xd

is this part of a question or something