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【单选题】
A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy’s hand but before it touches the ground, and assume that forces exerted by the air are negligible. For these conditions, the force(s) acting on the ball is (are)A.
a downward force of gravity along with a steadily decreasing upward force
B.
a steadily decreasing upward force from the moment it leaves the boy’s hand until it reaches its highest point; on the way down there is a steadily increasing downward force of gravity as the ball gets closer to Earth
C.
an almost constant downward force of gravity along with an upward force that steadily decreases until the ball reaches its highest point; on the way down there is only an almost constant downward force of gravity
D.
an almost constant downward force of gravity only.
E.
none of the above. The ball falls back to ground because of its natural tendency to rest on the surface of the Earth.
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