题干

关于伽利略对自由落体运动的研究,以下说法正确的是(   )

A:伽利略认为在同一地点,重的物体和轻的物体下落快慢不同

B:伽利略猜想运动速度与下落时间成正比,并直接用实验进行了验证

C:伽利略通过数学推演并用小球在斜面上验证了位移与时间的平方成正比

D:伽利略用小球在斜面上验证了运动速度与位移成正比

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答案(点此获取答案解析)

C

同类题5

阅读理解

B

    “Mum, may Patti come over?” asked Meg.

    “Not until you clean your room,” replied Mum.

    Meg said on the phone unhappily, “I have to clean my room first.”

    At the other end, Patti laughed. She said to Meg, “That's funny. My mum just said I can't go anywhere until I clean my room.”

    After hanging up (挂断电话), the girls went to their own rooms. Each girl looked around at her mess. Slowly they started cleaning their rooms.

    Meg said to herself, “Maybe we could talk on the phone while we work. It would be hard to work and talk at the same time, though.”

    Patti thought, “Until I clean my room, I can't leave. Meg may leave, but she can't have anyone over.” Then Patti asked her mum, “Mum, may Meg come?” “Sure,” said Patti's mum. “Remember, you must have your room cleaned before leaving the house.”

    Patti ran to the phone and called Meg. “I've got an idea!” she told Meg.

    A few minutes later, Meg went over to Patti's house. Her mum allowed her to go because she promised to clean her room when she returned.

    While dancing, singing and talking, the girls worked. One hour later, the room became clean. It was fun! The room looked great. Patti's mum was happy. She called Meg's mum and told her everything. Meg's mum said Patti could come to help Meg.

    The girls quickly went to Meg's house. They worked and played until the room was clean. The girls learned that working together could make cleaning fun and easy!