Projectile motion – terminology review Which of the following statements about a projectile are correct?
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AA path traced by a projectile is called its trajectory.
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BThe initial speed imparted to a projectile is called the velocity of projection.
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CThe angle made with the horizontal at launch is called the angle of projection.
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Dall of the above
Answer
Correct Answer: all of the above
Explanation
Introduction / Context:Projectile motion is a fundamental topic in kinematics. It has a standard vocabulary that appears repeatedly in physics and engineering entrance exams. This question asks you to identify the correct terminology among common definitions.
Given Data / Assumptions:
- Projectile launched into a uniform gravitational field with negligible air resistance.
- Horizontal plane as reference for angles.
- Terminology follows standard physics textbooks.
Concept / Approach:The motion of a projectile decomposes into independent horizontal and vertical components. But irrespective of calculations, the names for path and launch parameters are fixed: trajectory (path), velocity of projection (initial speed and direction), and angle of projection (angle with the horizontal at launch).
Step-by-Step Solution:
Check statement (a): The locus of the projectile is the trajectory. Correct.Check statement (b): The initial velocity vector is called the velocity of projection. Correct.Check statement (c): The launch angle relative to the horizontal is the angle of projection. Correct.Since all three are true, the combined correct choice is “all of the above”.Verification / Alternative check:Typical formulae support the terms: for initial speed u at angle θ, the range R = u^2 sin 2θ / g and time of flight t = 2u sin θ / g are expressed using the velocity and angle of projection; trajectory y(x) = x tan θ − (g x^2) / (2 u^2 cos^2 θ) explicitly names the path as trajectory.
Why Other Options Are Wrong:
- Selecting only one statement ignores the fact that each definition is standard and correct.
Common Pitfalls:Confusing “angle of elevation” and “angle of projection”—for projectiles at launch, they coincide when the launch point is the observer’s eye level.
Final Answer:all of the above