A 20-Kg Mass Is Projected from the Edge of the Top

question 3

Multiple Choice

A 2.0-kg mass is projected from the edge of the top of a 20-m tall building with a velocity of 24 m/s at some unknown angle above the horizontal. Disregard air resistance and assume the ground is level. What is the kinetic energy of the mass just before it strikes the ground?

• A) 0.18 kJ
• B) 0.97 kJ
• C) 0.89 kJ
• D) 0.26 kJ
• E) 0.40 kJ

---

Definitions:

Antagonistic Muscles

Antagonistic muscles are pairs of muscles that work against each other to move a joint, with one muscle contracting while the other relaxes.

Golgi Tendon Reflex

A protective reflex that prevents muscle damage during excessive force generation by causing muscle relaxation.

Brachial Plexus

A network of nerves that originates from the spinal cord in the neck and supplies the arms and hands with sensory and motor function.

Muscles of Arm

Groups of tissues that contract to facilitate movement of the arm and hand, including flexion, extension, abduction, and adduction.