A 12-Kg Mass Is Projected from Ground Level with a Velocity

question 67

Multiple Choice

A 1.2-kg mass is projected from ground level with a velocity of 30 m/s at some unknown angle above the horizontal. A short time after being projected, the mass barely clears a 16-m tall fence. Disregard air resistance and assume the ground is level. What is the kinetic energy of the mass as it clears the fence?

• A) 0.35 kJ
• B) 0.73 kJ
• C) 0.40 kJ
• D) 0.68 kJ
• E) 0.19 kJ

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Definitions:

Striations

Parallel lines or grooves on a surface, often found in muscle fibers and certain crystals.

Myofibril

A long, slender contractile structure within muscle cells, composed of repeating units called sarcomeres, which are responsible for muscle contraction.

Actin

A protein that forms (together with myosin) the contractile filaments of muscle cells and is also involved in motion in other types of cells.