本题目来源于试卷: Space Time & Motion A.1 Kinematics，类别为 IB物理学
[单选题]
A projectile is fired at an angle above the horizontatvj)p-), 0uu/hkqg mel on the surface of Moon. .r h,gwv joog r+t516xWhich of the following statements is correct abotr v5r1gj,h +x.g o6wout its motion
A. The magnitude of the horizontal component of its velocity remains unchanged until it falls on the surface of the moon
B. The magnitude of the vertical component of its velocity remains unchanged until it falls on the surface of the moon
C. The magnitude of the horizontal component of its velocity decreases steadily until it falls on the surface of the moo
D. The magnitude of the vertical component of its velocity decreases steadily until it falls on the surface of the moon
参考答案: A
本题详细解析:
Explanation:The moon has no atmosphere. As there is no air drag, there's no change in the horizontal component of velocity. It does not decrease (making option C incorrect, and option A correct). The magnitude of vertical component decreases only while the projectile moves upwards. At its maximum height, the vertical component becomes zero and then starts increasing in the in the downward direction until it hits ground (making D incorrect). Option B is obviously incorrect as moon's gravitation keeps changing the vertical component.
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