A projectile is fired at 30o with momentum p. Neglecting friction, the change in kinetic energy when it returns to the ground will be:
Correct answer: A. Zero
- A. Zero
- B. 30%
- C. 60%
- D. 100%
Explanation
When a projectile is fired at 30° with momentum p, neglecting friction, the change in kinetic energy when it returns to the ground will be zero. This is because according to the law of conservation of energy, the total energy remains constant in the absence of external forces like air resistance. Therefore, the initial total energy equals the final total energy, resulting in a change in kinetic energy of zero. The other options are incorrect as they misrepresent the relationship between launch angle and change in kinetic energy.
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Displacement, velocity and acceleration describe motion, including the horizontal and vertical components of projectile motion. The chapter connects these quantities with Newton's laws, momentum and impulse, then applies conservation of momentum to collisions, distinguishing elastic collisions from inelastic ones.
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