Which of the following statements is correct for an object moving with constant speed?
A. It must have zero acceleration
B. Its velocity is constant
C. It may have acceleration
D. Its displacement equals distance
Answer: Option C
Solution (By JKExamLibrary)
Constant speed does not imply zero acceleration if direction changes, e.g., uniform circular motion has centripetal acceleration. Velocity may change direction. Displacement magnitude ≤ distance. So only option B is correct.
Explanation:
Sound requires material medium for mechanical wave propagation. Vacuum lacks particles to transmit vibrations. Light (EM wave) travels through vacuum. Memory tip: 'Sound = mechanical wave ⇒ needs medium; light = EM wave ⇒ no medium needed'. Fundamental wave property frequently tested in competitive exams to assess medium-dependence understanding.
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