4. a 60kg olympic runner leaps over a hurdle. if the runner's initial vertical speed for her jump is 2.2m/s,
how high will she lift her center of mass to lear the hurdle?

The weight might not be important, but her height is, and hurdles heights are from 27 inches to 42 inches in height

Explanation:

A woman who is 6 feet 8 inches tall, with a short torso and long legs might not need to jump if the hurdle is only 27 inches in height.

answer: option c. i.e. electric current flowing “downhill” from the negative electrode to the positive electrode in a battery

explanation:

the water analogy to the circuits define the pipes (water flows) to the electric current. now, we know that the electric current flows from the positive terminal to the circuit (as shown in the diagram attached).

hence, option c is the correct answer.

the independent variable, or the one that is intentionally manipulated is the speed.