[填空题]
A person sitting in an enclosed train car, moving at cn jhs; 9//*vefy rlc/2gzp g:konstant 0e ).lce0q:xzi nm4nkqve;u3velocity, throws a ball straight up into z0 ;3 )ixku0eqn:ce4v lmn. eqthe air in her reference frame.
(a) Where does the ball land? What is your answer if the car
(b) accelerates,
(c) decelerates,
(d) rounds a curve,
(e) moves with constant velocity but is open to the air?
参考答案: 空格1: in her hands
空格2: behind her
空格3: ahead of her
空格4: her left
空格5: behind her
本题详细解析:
(a)The ball lands at the same point from which it was thrown inside the train car – back in the
thrower’s hand.
(b)If the car accelerates, the ball will land behind the point from which it was thrown.
(c)If the car decelerates, the ball will land in front of the point from which it was thrown.
(d)If the car rounds a curve (assume it curves to the right), then the ball will land to the left of the
point from which it was thrown.
(e)The ball will be slowed by air resistance, and so will land behind the point from which it was
