If a dense 20.0-kg object is falling in air at half its terminal velocity, what is the drag force on the object at this moment?
A) 24.5 N
B) 49.0 N
C) 69.3 N
D) 98.0 N
E) 139 N

Question

Quizplus · Accepted Answer

When the object is falling at half its terminal velocity, its acceleration is half of the acceleration due to gravity (9.8 m/s²). Thus, its acceleration is 4.9 m/s². At this point, the net force on the object is equal to the gravitational force on the object minus the drag force on the object. Using Newton's second law, we can write:

Fnet = ma
mg - Fdrag = ma
Fdrag = mg - ma

Substituting the given values, we get:

Fdrag = (20.0 kg)(9.8 m/s²) - (20.0 kg)(4.9 m/s²) = 98.0 N - 49.0 N = 49.0 N

Therefore, the drag force on the object at this moment is 49.0 N.

If a Dense 20