If a runner exerts a vertical force of 2000 N, and the coefficient of static friction between the shoe and the ground is 0.50, what is the maximum horizontal force he can generate under his shoe?

A shot put is released with a velocity of 14 m/s at an angle of 42 degrees. What are the vertical and horizontal components of velocity? (Article example)

A baseball is thrown with a horizontal velocity of 47.0 m/s and a vertical velocity of 4.1 m/s. What is the resultant velocity (magnitude and direction)?

Another resultant force in running

A 70 kg runner experiences air resistance of 15 N. During the heelstrike, he exerts an A/P force of 100 N. The vertical ground reaction force at this time was 1300 N.

Draw a diagram of this situation and determine the resultant force (magnitude and direction relative to horizontal).

Static Equilibrium

When an object is at rest and the forces acting on the object are in equilibrium, they result in a net force of zero.

Weightlifter example: Person's mass=80kg, barbell=70kg, ground reaction force=1470N.
Is this system in static equilibrium?