Question

The wind force f on a sail varies jointly as the area a of the sail and the square of the wind speed w.

Answer 1

Answer:

  122.5 lbs

Step-by-step explanation:

The relation between force, wind speed, and area can be written ...

  f = ks²a

for some wind speed s and area a.

__

The constant of proportionality, k, can be found from the given data.

  64.8 = k(18²)(500) . . . force in pounds, area in square feet, speed in mph

  k = 64.8/(324×500) = 0.0004

__

Using the equation with the second set of data, we have ...

  f = 0.0004(35²)(250) = 122.5 . . . . pounds

The force on the 250 square foot sail would be 122.5 pounds.