5.

When an object is falling, the air resistance, A varies directly as the square of

the speed, S. At a certain speed the resistance is 60 newtons. What is the

resistance at twice this speed?

240 N

Step-by-step explanation:

Resistance force (A) varies directly with the square of the speed (S).

A = k S²

At a certain speed (S = s), the resistance is A = 60.

60 = k s²

k = 60 / s²

At double the speed, (S = 2s), the resistance is:

A = k (2s) ²

A = (60 / s²) (2s) ²

A = (60 / s²) (4s²)

A = 240