A hook in boxing primarily involves horizontal flexion of the shoulder while maintaining a constant angle at the elbow. During this punch, the horizontal flexor muscles of the shoulder contract and shorten at an average speed of 75 cm/s. They move through an arc length of 5 cm during the hook, while the fist moves through an arc length of 100 cm. What is the average speed of the fist during the hook

average speed of the fist during the hook = 15 m/s or 1500 cm/s

Explanation:

We are given;

Speed of shoulder contraction, v_s = 75 cm/s = 0.75 m/s

Distance moved through the arc length by shoulder, d_s = 5 cm = 0.05 m

Distance moved by the fist, d_f = 100 cm = 1 m

Now, we are to find the average speed of the fist during the hook; v_f

Thus can be gotten from proportion;.

d_f/d_s = v_f/ v_s

Making V_f the subject, we have;

v_f = (d_f × v_s)/d_s

Thus;

v_f = (1 × 0.75)/0.05

v_f = 0.75/0.05

v_f = 15 m/s

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

it was given as a lesson and guide for prayer.