Question

in an experiment designed to measure the distance a golf ball is hit by clubs made of different material, all of the variables would be standardized except
the wind direction when the experiment takes place.
the force used to hit the ball.
the type of material the golf ball is made of.
the type of material the club is made of.
the angle the ball is hit.

Explanation:

In an experiment, standardized variables (controlled variables) are kept constant to isolate the effect of the independent variable. The goal here is to test how club material affects hit distance, so the club material is the independent variable that must not be standardized. All other listed factors (wind direction, hitting force, golf ball material, hitting angle) need to be kept consistent to ensure only club material impacts the outcome.

Answer:

the type of material the club is made of.