A20.0-kg package is dropped from a high tower in still air and is "tracked" by a radar system. when the package is 25 m above the ground, the radar tracking indicates that its acceleration is 7.0 m/s2. determine the force of air resistance on the package.

56 N

Explanation:

There are only two forces acting on the package:

- The force of gravity, directed downward, equal to

where m is the mass of the package and g is the acceleration due to gravity

- The air resistance, acting upward, let's label it with

According to Newton's second law, the resultant of the two forces must be equal to the product between the mass, m, and the acceleration, a:

where we have:

m = 20.0 kg

g = 9.8 m/s^2

a = 7.0 m/s^2 is the acceleration when the package is at 25 m above the ground.

Substituting into the equation, we can find the magnitude of the air resistance at that altitude:

think its the third option