A water skier has a mass of 73 kg. Find the magnitude of the net force acting on the skier when she lets go of the tow rope and glides to a halt in 20 s.

To find the magnitude of the net force acting on the skier, we can use Newton's second law, which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration.

First, we need to find the acceleration of the skier. We know that the skier glides to a halt, which means her final velocity is 0 m/s. We also know that the time taken to glide to a halt is 20 s.

We can use the equation of motion:
final velocity = initial velocity + acceleration x time

Since the final velocity is 0 m/s, the equation becomes:
0 = initial velocity + acceleration x 20

The initial velocity is not given in the question. However, since the skier is letting go of the tow rope, it is safe to assume that the skier's initial velocity can be considered approximately 0 m/s (assuming the skier was initially moving at a steady speed).

Substituting the values into the equation:
0 = 0 + acceleration x 20

Simplifying the equation:
0 = 20 x acceleration

Therefore, the acceleration of the skier is 0 m/s^2.

Now, we can calculate the net force using Newton's second law:
Force = mass x acceleration

Substituting the values into the equation:
Force = 73 kg x 0 m/s^2

The acceleration is 0 m/s^2, so the net force acting on the skier is 0 Newtons.