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.

a, c, d, e are all applying about success strategies.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia